lcd screen power consumption manufacturer

The power consumption of computer or tv displays vary significantly based on the display technology used, manufacturer and build quality, the size of the screen, what the display is showing (static versus moving images), brightness of the screen and if power saving settings are activated.

Click calculate to find the energy consumption of a 22 inch LED-backlit LCD display using 30 Watts for 5 hours a day @ $0.10 per kWh. Check the table below and modify the calculator fields if needed to fit your display.

Hours Used Per Day: Enter how many hours the device is being used on average per day, if the power consumption is lower than 1 hour per day enter as a decimal. (For example: 30 minutes per day is 0.5)

LED & LCD screens use the same TFT LCD (thin film transistor liquid crystal display) technology for displaying images on the screen, when a product mentions LED it is referring to the backlighting. Older LCD monitors used CCFL (cold cathode fluorescent) backlighting which is generally 20-30% less power efficient compared to LED-backlit LCD displays.

The issue in accurately calculating the energy consumption of your tv or computer display comes down to the build quality of the screen, energy saving features which are enabled and your usage patterns. The only method to accurately calculate the energy usage of a specific model is to use a special device known as an electricity usage monitor or a power meter. This device plugs into a power socket and then your device is plugged into it, electricity use can then be accurately monitored. If you are serious about precisely calculating your energy use, this product is inexpensive and will help you determine your exact electricity costs per each device.

In general we recommend LED displays because they offer the best power savings and are becoming more cheaper. Choose a display size which you are comfortable with and make sure to properly calibrate your display to reduce power use. Enable energy saving features, lower brightness and make sure the monitor goes into sleep mode after 5 or 10 minutes of inactivity. Some research studies also suggest that setting your system themes to a darker color may help reduce energy cost, as less energy is used to light the screen. Also keep in mind that most display will draw 0.1 to 3 watts of power even if they are turned off or in sleep mode, unplugging the screen if you are away for extended periods of time may also help.

The change is quite small in comparison to overall display power consumption, but it held true across multiple display panel types (TN, IPS), and backlight sources (CCFL, LED).

It seems the power variance is somewhat dependent on the LCD in question. However, I tested three different LCDs, which use different panel types (TN, IPS), Backlight sources (LED, CCFL), and the increase in energy to display a black subject was common across all of them.

The power draw is specified in ranges because the readout measurement on the Kill-A-Watt is somewhat noisy. I took measurements by letting the monitor sit at the specified display image for a minute or two, then monitored the maximum and minimum value displayed on the Kill-A-Watt. Those are the numbers reported for the range in each monitor"s power draw.

The Only situation where something like Blackle would be of use, or indeed beneficial is with OLED Screens. These screens effectively have a backlight-per-pixel, and they do indeed save power when displaying dark scenes.

However, with any modern single-backlight LCD, the only effect on power draw is the actual panel"s power draw, which increases as the transmitted light decreases, the inverse of what Blackle claims.

Reflective LCD displays, such as 7 segment displays, have been around for a long time. We recognize them from all kinds of household appliances including thermometers, ovens, watches, toys and medical devices. Until recently, LCD has been the only option for low power but now two alternative technologies exist on the market; the E-Paper display based on electrophoresis and the Ynvisible Display based on electrochromism, both offering features that LCD is lacking.

In this article, we investigate Electrophoretic displays (E-Paper), Reflective LCDs and the Ynvisible Segment Display from a power perspective. All these technologies are categorized as reflective displays. Reflective displays are essentially required for ultra low power applications since emitting light is very power consuming. We want to clarify that displays from different manufacturers have slightly different energy consumption, and the data presented here is an average from the suppliers with the most energy efficient displays.

Before we go too deep it is important to understand the driving requirements of each display technology. Reflective LCD displays need an active driver that varies the polarity of the voltage across the pixel in a frequency of about 60Hz. E Paper, on the other hand, doesn"t need any active control once the display has been updated, this feature is often referred to as bistability. Ynvisible Displays is somewhere in between LCD and E-Paper; once the display has been switched the controller can go idle for about 15 minutes (there exist versions that can be idle for up to 24 hours as well). We usually call this phenomenon "semi-bistability". After this time a small refresh pulse is required to maintain the state. For E-Paper and Ynvisible Displays, energy is only required during switching and updating while no energy is consumed during idle state. Typically, the energy required for a full switch on an E-Paper display is about 7 to 8mJ/cm2. The corresponding number for the Ynvisible Segment Display is about 1mJ/cm2 with the addition of 0,25mJ/cm2 every 15-60 minutes. LCD continuously consumes about 6µW/cm2.The energy consumption depends on how often the content is changed.

Followed by the different driving characteristics of the displays, we need to look into how often the display is updated to truly understand which display is the most energy efficient for your specific application. This is done by calculating the average power as a function of the number of switches per day. As seen in the diagram the E-Paper display is the most power effective choice if the application is switching less than four times a day. Between 4 and 600 switches, the Ynvisible Display is the most energy efficient choice. If the display switches more than 600 times a day reflective LCD would be the best option from a power perspective.

To summarize the findings we can conclude that the Ynvisible Segment Display is the most power efficient choice if you need a display that is supposed to switch 4-600 times a day. However, we need to remember that there might be other features to take into consideration as well. For example, the Ynvisible Segment Display is flexible in its standard format and can be offered in multiple different colors without additional cost.

New LCD flat panel displays are constantly reaching record lows in power consumption: 50 W, 40 W, and even 30 W are sometimes achieved in displays as large as 24” these days. The most important variable in display power savings is the backlight technology. Today, we have fluorescent lighting transitioning to light-emitting diodes (LEDs). We grabbed all of our test lab"s LCD monitors and two old CRTs, pitting them against each other in a power consumption shootout.

As of late, we"ve written a lot about power consumption on the system side, where usage is most noticeable. Processors and graphics cards were particularly blatant consumers a few years ago. Nowadays, the trend (especially in Europe) is mostly toward more environmentally-friendly components.

Green computing has forced even the largest corporations to rethink and refocus. We have low-power processors, motherboards, memory modules, hard drives, and even high-efficiency power supplies. Many things have changed, but you still need to look at every product individually to decide whether or not it’s truly efficient.

Interestingly, displays were largely neglected in this "green refresh." Part of the reason was that, ever since LCDs displaced CRT displays, the typical PC utilizes more power than its attached monitor. However, this is changing rapidly. Enthusiast PCs, gaming systems, and workstations still often consume more than 100 W at idle and much more under load. But the majority of PCs sold are business and mainstream systems, and the average power consumption in this group is dropping fast thanks to aggressive optimization.

As a result, mainstream PCs that don’t sport discrete graphics and multi-core processors consume reasonable amounts of power. In the article Build a 25 W Performance PC Using Core i5, we proved that a system with above-average performance does not have to draw more than 25 W at idle. Since most 20" or higher flat panels consume 30 or 40 W, it"s likely that your display will chew up more power than your nettop or mainstream system.

Monitors display visual content to their users. There is a wide variety of monitors available in the market. It ranges from sizes to models and manufacturers. However, the greater dilemma is its power consumption.

Power consumption is affected by monitor size, model, and emitter. Furthermore, it also depends on the build quality, screen brightness, and power-saving settings. However, the manufacturer and the model type make a significant difference.

There are also some things you need to understand about the power consumption of monitors that will ultimately make a lot of difference in whether or not you decide to go with one, especially in terms of choosing one. To reduce the power consumption, you must determine how much you’re already consuming.

In this article, we’ll provide an in-depth review of the power consumption of different monitors. Firstly, we’ll look at different types of monitors and their power consumption. Then we’ll illustrate different monitor modes that affect electricity consumption.

To get an idea of why some PC monitors use more power than others, we’ll have to consider the material they are made from. Here are 4 types of monitors.

CRT or Cathode Ray Tube monitors are huge and bulky in size. They are made of a vacuum tube with heaters, circuits, and electron guns. They’re no longer used because of their power consumption and manufacturing costs. The average power consumption of a typical 19-inch display is about 100 watts.

LCD monitors are the most popular type of monitor. These monitors use transparent electrodes and polarizing filters. Also, these monitors provide better quality and are much easier to manufacture. In addition, they are thin and light. Hence, the average power consumption for this type of monitor is about22 watts for a 19-inch display.

LED monitors are the latest technology in the market. Similar to LCD, LED monitors are also flat and thin. However, it consists of a slightly curved display that utilizes LED technology. They consume much less power than LCD and CRT monitors. For a typical 19-inch display, the power consumption is about 20 watts.

As compared to LED and LCD, Plasma monitors utilize gas-filled technology. The gas-filled cells are placed between two parallel glass surfaces, and the screen lights up with the help of ultraviolet radiation. However, they are much more costly than LCD and LED monitors. For a 19-inch display, the power usage is around 38 watts.

The number of watts a monitor uses also depends on its operating mode. There are a total of three modes that an average monitor has. However, keep in mind that the power consumption may vary depending on the model and the manufacturer. Let’s look at the three operating modes.

Shutdown Mode:In this mode, the monitor is off except for its power light. Only the red LED light appears, indicating it is in Shutdown Mode. However, it still consumes between 0 to 5 watts unless you switch off the power source.

Now that we’re familiar with the monitor technology and its power usage, let’s have a look at the final summary of the power consumption of each type of monitor.

Just remember that these power usages may vary slightly. These estimations are average, and some monitors might cost you more in terms of power consumption depending on your location and electricity unit per hour.

And that’s a wrap. The article has provided a brief guide on how many watts a monitor uses. As long as you keep your monitor on standby, you aren’t consuming much power compared to other household equipment. Additionally, you can save a lot more by fixing the heating, cooling, and lighting issues with your monitor.

Monitors typically use 5 to 10 watts when they are in Sleep Mode. Although the measurements are average, they may consume a little more power. However, they won’t consume more than the limit.

While searching for an appropriate LED display screen, power consumption turns out to be one of the important factors. While size, pixel pitch and resolution play a significant role in the selection, power efficiency finalizes the decision with the certainty of how much electricity cost they will be spending.

LED displays used to produce visual images from the input source with the help of individual diodes or pixels using different colors and intensities. When it comes to creating a full black screen, diodes do not work in any way whereas, for a white screen, all get to the work and stay at their maximum until needed.

According to the experts, maximum power consumption refers to a situation when the display screen works on its full power with brightness to its optimum for creating full white content. The power utilized so measured is considered to be at its maximum with small margin for environmental factors.Black Level Power Utilization

It is a type of power consumption that enables other components, except for LED, to work without creating content. In other words, diodes are off while the receiver cards and drivers are at work and therefore, utilize some energy.Standby Power Consumption

When the LED displayis in standby mode, the same components get into the power saving mode and still need some power to keep working. This power consumption is quite below the black level. A worth mentioning fact is that content is not necessarily be white or black, it is also in different colors based on the purpose for which it is installed.

After getting to know about power consumption indicators, below are some factors to take into consideration:Time scheduling: LED display power consumption can be controlled with the help of a software application. Users can also adjust brightness settings with respect to the need of the time, thereby ensuring the best display images in the result.

Attenuation Characteristics: After working for a certain time period, the brightness level will start to decrease. This causes inconsistencies in the color formation as well as brightness attenuation of green, blue and red LEDs. With 1000 hours of power i.e. 20.A, red attenuation must be below 2% while green and blue attenuation must be 10% or less. This means that green and blue LEDs do not use 20mA electricity, meaning that electricity has a significant impact on attenuation characteristics.

Mode of Operation: LED drivers are designed to provide consistent, regulated and sufficient power supply a constant current driver (CC) or single-module solution is responsible to regulate current directly to the LED.

Application Power Requirements: Over the couple of years, the power-handling abilities of single-chip, white LEDs have evolved from a few milliwatts to watts. Even, their light output efficiency, usually in lumens per watt, moved from 10 lumens/watt to over 100 lumens/watt. As for the modern LED lighting, lighting may be anywhere from 1 watt to hundreds of watts. Also, remember that shape and size will be different along with the functions and features.

Theoretically, LED pixels used to work at 5 volts with 20mA current., which means that energy consumption by each pixel is 0.1 (5V x 20mA). Buyers can easily determine the total power consumption of the LED display.

Considering the need to save energy in one way the other,led display manufacturers introduced a number of energy efficient LED displayscreens having advanced technology. What makes these LEDs different is the voltage consumption that is as low as 2.8 volts, thereby saving around 50 percent of energy.

Power consumption and its expenses depend upon the electricity rate, brightness level and resolution of the display screen. Below is the table showing estimations of energy consumption of outdoor and indoor LED display that can help buyers to come up with the right option they can afford based on their budget:Display TypeMax Brightness Level (nits)Average Energy Consumption (W/m2)Average Energy Cost (Annual) (in dollars $/m2)

Power consumption is a decisive parameter when comparing LED displays. If you are researching into your options for an LED wall you might have wondered why the power consumption values for certain LED products are higher than others. The answer is simple: the values are based on different calculations. And you shouldn’t compare apples and oranges. So allow us to demystify the seemingly inexplicable differences in the LED power consumption specifications.

Energy efficiency closely relates to the total cost of ownership of your product (TCO). Restricted power consumption levels mean electricity expenses are kept to a minimum. In addition, it goes without saying that power consumption is crucial when it comes to sustainability objectives. Energy efficient products also reduce your eco-footprint and are generally better for the environment.

So yes, you should definitely look at the power consumption information when deciding on a new LED video wall, but be aware that in order to make a thought-through decision you need transparent spec information.

LED recreates the visual content sent from the input source by lighting up the individual pixels or diodes to different intensities and colors. To show a full black screen, for instance, all diodes are switched off; whilst to present a full white screen, all diodes are powered to their maximum.

The maximum power consumption is defined by recreating a situation where the LED wall is going full power, the product is set to full brightness showing full white content for a certain amount of time. The power consumption measured in this way is the maximum power consumption spec of your product, of course taking into account a small additional margin for environmental variables.

Black level power consumption refers to the power needed to run the electronics without showing content on the LED wall. Because even though the diodes are off, the drivers and receiver cards are still consuming energy.

When the LED wall is set in standby those same electronics are still working albeit in power saving mode. So, the standby power consumption is below the black level power consumption, but obviously still higher than when the display is completely turned off.

Now, content usually isn’t just full black or white, but shows a variety of colors depending on the application where LED wall is used for. That’s why Barco always refers to “the typical power consumption”.

The traditional industry rules of thumb (dividing the maximum power consumption by three) usually don’t take into account the average use and black level power consumptions. For outdoor products with low pixel density and only a couple of drivers, this was on average a correct calculation. But with today’s high-resolution indoor LED products, the black level power consumption has become an important parameter which shouldn’t be left unnoticed. Pixel-pitches are significantly lower, think of the XT0.9 tile, and the pixel density on LED tiles is increasing. More pixels naturally need more drivers to manage the wall. The power consumed by these drivers and extra electronics is not neglectable. Hence, it’s only logical to include it in your calculations. The result will be much closer to reality!

Barco’s calculation of the typical power consumption is based on the black level power consumption, the maximum power consumption and an average usage of the LED wall. On average a customer configures the display at 70% of its maximum brightness, and the typical content on the wall consumes only 33% of that power.

In this calculation we assume that the content consumes only 33% of the configured power, but as we indicated earlier it all depends on the application area and the typical content shown on the display. Suppose you install an LED wall in a lobby to welcome your business visitors by showing your logo and the visit’s schedule on a white background. Since the white requires more power, the average power consumption of this content will be higher than 33%, and the total typical power consumption for this specific case will also result in a higher number. If you install the same LED wall in a control room where predominantly black SCADA1 content is shown, the average power consumption will be lower than 33% and the typical power consumption significantly smaller than in the lobby.

Yes, one and the same LED wall can have different typical power consumption levels in different environments! Each application has its own typical visualized content which has a huge impact on the typical power consumption.

For small/medium size televisions, LCD is clearly the choice for those of you with limited power. The other great news is that they are getting cheaper as time goes on. Coles and a number of supermarkets are now selling 38 cm LCD televisions for under AUS$200.

I say "if" because they are designed to run off a 230V-12V regulated power supply. This is not the same as running it direct from a 12V solar system where the battery voltage can easily range from 11 to 15 volts. An even wider variance is possible with flat or failing batteries; a battery system being equalised to 15.5-16 volts etc.

There appears to be a few brands that can definitely be run off a battery and these are marketed to the caravan and yachting market. Majestic LCD televisions will operate between 10.9 and 15.5 volts. Xien sell a range for the marine industry. Sharp televisions are also sold as "12 volts" but come with a $140 special 12 V lead. I suggest this has a power conditioner on it. Dick Smith once sold (and may still do so) an AC/DC 15 inch model.

The power "saving" of being able to run it direct is significant. From my observations, the 230 to 12V adapter supplied with the television is only about 50% efficient. By the time you then use an inverter to change your 12V to 230V, I estimate that you could be tripling your power consumption.

For the "big end of town", a consumer magazine tested 4 popular brands of large LCD and Plasma televisions for power consumption. Interestingly, the 45/ 46 inch Plasma televisions used 260 –286 watts while the 42/43 inch Plasma televisions used significantly less (183- 186 watts). All four used between 0.67 and 1.4 watts on stand by.

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, digital clocks, calculators, and mobile telephones, including smartphones. LCD screens are also used on consumer electronics products such as DVD players, video game devices and clocks. LCD screens have replaced heavy, bulky cathode-ray tube (CRT) displays in nearly all applications. LCD screens are available in a wider range of screen sizes than CRT and plasma displays, with LCD screens available in sizes ranging from tiny digital watches to very large television receivers. LCDs are slowly being replaced by OLEDs, which can be easily made into different shapes, and have a lower response time, wider color gamut, virtually infinite color contrast and viewing angles, lower weight for a given display size and a slimmer profile (because OLEDs use a single glass or plastic panel whereas LCDs use two glass panels; the thickness of the panels increases with size but the increase is more noticeable on LCDs) and potentially lower power consumption (as the display is only "on" where needed and there is no backlight). OLEDs, however, are more expensive for a given display size due to the very expensive electroluminescent materials or phosphors that they use. Also due to the use of phosphors, OLEDs suffer from screen burn-in and there is currently no way to recycle OLED displays, whereas LCD panels can be recycled, although the technology required to recycle LCDs is not yet widespread. Attempts to maintain the competitiveness of LCDs are quantum dot displays, marketed as SUHD, QLED or Triluminos, which are displays with blue LED backlighting and a Quantum-dot enhancement film (QDEF) that converts part of the blue light into red and green, offering similar performance to an OLED display at a lower price, but the quantum dot layer that gives these displays their characteristics can not yet be recycled.

Since LCD screens do not use phosphors, they rarely suffer 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 are, however, susceptible to image persistence.battery-powered electronic equipment more efficiently than a CRT can be. By 2008, annual sales of televisions with LCD screens exceeded sales of CRT units worldwide, and the CRT became obsolete for most purposes.

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, along with OLED displays, 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 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 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,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.

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),

Due to the LCD layer that generates the desired high resolution images at flashing video speeds using very low power electronics in combination with LED based backlight technologies, LCD technology has become the dominant display technology for products such as televisions, desktop monitors, notebooks, tablets, smartphones and mobile phones. Although competing OLED technology is pushed to the market, such OLED displays do not feature the HDR capabilities like LCDs in combination with 2D LED backlight technologies have, reason why the annual market of such LCD-based products is still growing faster (in volume) than OLED-based products while the efficiency of LCDs (and products like portable computers, mobile phones and televisions) may even be further improved by preventing the light to be absorbed in the colour filters of the LCD.

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.

A comparison between a blank passive-matrix display (top) and a blank active-matrix display (bottom). A passive-matrix display can be identified when the blank background is more grey in appearance than the crisper active-matrix display, fog appears on all edges of the screen, and while pictures appear to be fading on the screen.

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.

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.

Low power consumption. Depending on the set display brightness and content being displayed, the older CCFT backlit models typically use less than half of the power a CRT monitor of the same size viewing area would use, and the modern LED backlit models typically use 10–25% of the power a CRT monitor would use.

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.

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.

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.

Only one native resolution. Displaying any other resolution either requires a video scaler, causing blurriness and jagged edges, or running the display at native resolution using 1:1 pixel mapping, causing the image either not to fill the screen (letterboxed display), or to run off the lower or right edges of the screen.

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.

Dead or stuck pixels may occur during manufacturing or after a period of use. A stuck pixel will glow with color even on an all-black screen, while a dead one will always remain black.

In a constant-on situation, thermalization may occur in case of bad thermal management, in which part of the screen has overheated and looks discolored compared to the rest of the screen.

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".

Critics of the report point out that it assumes that all of the NF3 produced would be released to the atmosphere. In reality, the vast majority of NF3 is broken down during the cleaning processes; two earlier studies found that only 2 to 3% of the gas escapes destruction after its use.3"s effects with what it replaced, perfluorocarbon, another powerful greenhouse gas, of which anywhere from 30 to 70% escapes to the atmosphere in typical use.

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