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Note: All the instructions below take the control panel window as showing its default settings. (for example, Control Panel comes set to Category View, you can then change it to Large or Small Icon View.)
Note: If new settings do not work, Windows® attempts to revert back to the original settings automatically. If the video has become corrupted or an Out of Scan Range error occurs that cannot be automatically corrected, restart the computer. Press during startup, highlight Safe Mode from the Startup Menu, and then press to start the computer in Safe Mode. In Safe Mode, change the screen resolution back to the original settings and restart normally.
Note: Adjusting the refresh rate is only recommended for cathode-ray tube (CRT) monitors, and is unnecessary for laptop LCD screens or flat-panel LCD monitors.
Note: If new settings do not work, Windows® attempts to revert back to the original settings automatically. If the video has become corrupted or an Out of Scan Range error occurs that cannot be automatically corrected, restart the computer. Press during startup, highlight Safe Mode from the Startup Menu, and press to start the computer in Safe Mode. In Safe Mode, change the screen resolution back to the original settings and restart normally.
Under the Change the size of text, apps, and other items title, click the drop-down box. Then select the font size that you want from the drop-down box.
In this article, we"ll look at the gradations that result from the maximum number of colors that can be displayed and the look-up table (LUT). While these factors are a step beyond what average users consider when choosing products, they have a significant impact on color reproduction. Users are well-advised to understand these factors, especially when choosing an LCD monitor for color-intensive applications like photo retouching or design work.
Note: Below is the translation from the Japanese of the ITmedia article "Maximum Display Colors and Look-Up Tables: Two Things to Consider When Choosing a Monitor" published February 18, 2009. Copyright 2011 ITmedia Inc. All Rights Reserved.
While most LCD monitor catalogs show the maximum number of colors each model can display, few people pay much attention to this figure. That"s because most products today can display a staggering number of colors—more than 16 million. Users are unlikely to be dissatisfied because the product displays too few colors. However, the figure for maximum number of colors is associated with some unexpected pitfalls.
The LCD monitors currently available for PC use need to accurately display full-color video signals in the number of colors generated when using eight bits for each RGB color (for a total of 24 bits) input from the PC. Using eight bits for each RGB color, we can generate roughly 16.77 million colors, based on the following calculations:
We need to keep two points in mind: First, not all leading LCD monitors can reproduce the entire full color range of approximately 16.77 million colors. Second, this full color range of 16.77 million colors can be achieved in different ways. The LCD monitors currently available generally fall into the following three categories with respect to the maximum number of colors and method of color reproduction.
Only the Type 1 LCDs in the table above achieve full color in the true sense of the term, reproducing each RGB color at eight bits on an LCD panel operating at eight bits. Products that fall into Types 2 or 3 offer so-called virtual full color. Virtual full color products cost less to implement, but generally offer inferior capacity to express gradation than true eight-bit LCD panels.
When we look at monitor specs, it"s easy to identity a Type 3 model: The number of colors will be specified as 16.19 or 16.20 million. However, since both types 1 and 2 show approximately 16.77 million colors it can be difficult to identify the applicable type from a catalog. An LCD panel operating at eight bits is superior in some ways with respect to picture quality, and users are advised to be careful when choosing monitors for graphics applications. (Note that in some cases, the figure of 24 bits—eight for each RGB color—is used instead.)
Certain LCD televisions and LCD monitors for commercial use are based on LCD panels that reproduce each RGB color at 10 bits. In theory, these monitors can generate 1,073,741,824 (or approximately 1.073 billion) colors; but they also require graphics accelerators and software capable of handling 10-bit color. For these reasons, they are not yet common in the PC industry.
Let"s consider at a simple description of frame rate control (FRC). FRC is a system for increasing the number of apparent colors by manipulating the frame rate, taking advantage of afterimage effects in the human eye. Switching rapidly between white and red, for example, will create what the human eye perceives as pink.
An LCD panel with six-bit operation plus FRC can actually generate just 262,144 colors (six bits [26 = 64] to the third power [for each RGB color]). We can apply FRC to each RGB color and change the display interval between each of the LCD panel"s original colors (in the case of four-bit FRC) to generate three simulated colors between each pair of individual colors. For each RGB color, this adds the following number of simulated colors: (6 bits – 1) * 3 = 189 colors. We obtain the total number of colors by calculating (6 bits + 189 = 253) to the third power (each RGB color) = 16,194,277 colors (≈ approximately 16.19 or 16.20 million colors).
More and more recent products feature technologies that take FRC one step further. These technologies make it possible to reproduce approximately 16.77 million colors by operating the number of bits exceeding those with traditional FRC to generate even more stimulated colors, then taking from these the eight-bit (256-gradation) scale needed to achieve full color on an LCD monitor.
Under real-life conditions, factors other than the panel, such as quality of ICs for image control, can also significantly affect picture quality. The difference in picture quality between eight bits and six bits plus FRC is often not apparent on visual inspection. Minimizing environmental lighting (for example, by dimming lights) can make such differences easier to spot. Displaying gradation patterns that change linearly, one going from shadow to highlight, can also highlight such differences. Such display tendencies apply equally to still images, moving images, games, and other applications.
Sample gradation display using a full-color display operating at eight bits (left) and virtual full-color display operating at six bits plus FRC (right). While this display exaggerates the difference to make it easier to see, eight-bit operation generally offers greater gradation display capability.
We"ve noted that six-bit operation plus FRC is inferior to eight-bit operation in terms of gradation display capability. However, this doesn"t mean eight-bit operation is always superior with respect to color reproduction and gradation. The look-up table (LUT) is a key factor in an LCD monitor"s ability to display tonal grades and transitions.
In the context of LCD monitors, the term LUT refers to a component that calculates input signals from the PC (at eight bits per RGB color) and maps them to output signals suited to the LCD monitor (also at eight bits per RGB color). An inexpensive LCD monitor will employ an LUT table with eight bits per RGB color; an LCD monitor designed for color reproduction applications will incorporate an LUT with more than eight bits (i.e., 10 or 12 bits) per RGB color and employ internal calculations at 10 or more bits to map input signals to output signals.
Diagram of procedural flow from the input of a video signal to display on screen for an LCD monitor with LUT and internal precision exceeding eight bits. Target gamma attributes (i.e., 1.8 or 2.2) are determined in advance based on calculations assuming no difference between individual LCD panels. Since determining target gamma attributes alone will not result in correct color temperatures, the color space is calculated at a precision greater than eight bits, and a color gamut covering the color temperature of white is configured. Corrections on the output side offset differences between individual LCD panels and result in a smooth tone curve. An LUT of more than eight bits allows color displays with more subtle tonal variations.
How does an LUT with more than eight bits improve display quality? If a catalog says an LCD monitor is capable of displaying "approximately 16.77 million (of 1,064,330,000)" colors, the unit incorporates an LUT of 10 bits per RGB color (1024 gradations to the third power = 1,064,330,000 colors). Specifically, the input signal from the PC, with eight bits per RGB color, is subjected to multi-gradation within the LCD monitor at 10 bits per RGB color, then output at the optimal display colors at eight bits per RGB color. This results in significantly smoother tonal transitions and improves hue divergence by improving the gamma curve of each RGB color in the output. A 12-bit LUT generates approximately 16.77 million optimal colors from roughly 68 billion, improving color reproduction and gradation beyond even a 10-bit LUT.
Next, let"s look at calculations for multi-gradation of an eight-bit per RGB color input signal at 10 or more bits per RGB color within an LCD monitor. Even if we use a 10- or 12-bit LUT, calculating multi-gradation at 14 or 16 bits will result in even more precise final tonal transitions. The need for 16-bit precision when the final output is only eight bits may not be obvious, but particularly when we seek to depict subtle differences between colors at a low-gradation gamut (shadow gamut), the precision of internal calculations is extremely important. In essence, the higher the number of bits used in the internal calculations, the closer the gamma curve in a low-gradation gamut to the theoretical curve.
A look at the current range of LCD monitors shows that even in lower-cost categories, growing numbers of products offer 10-bit LUTs. Nevertheless, only products at the top of their class have bit counts greater than LUT bit counts. In particular, models that process colors to the most stringent requirements, using 12-bit LUTs and 14- or 16-bit internal calculations, are ideal for color management use, targeting applications that require high-performance color.
Visual comparisons of a monitor employing an eight-bit LUT and eight-bit internal calculation with one incorporating an LUT of 10 or more bits and internal calculations of 10 or more bits shows unexpected differences. Since the latter class of products tends to feature high-performance ICs for image control, differences in picture quality are likely to be even more apparent to a discerning viewer than for entry-level products associated with inconsistent performance. When we examine the grayscale chart, models with higher bit-count LUTs and internal calculations tend to produce smoother tonal transitions and better representation of tones in shadow areas. Such products have almost no tone jumps or hue divergence and offer stable contrast in which lightness and darkness in gradation are depicted naturally. For all these reasons, we recommend a product with at least a 10-bit LUT—not just for applications that require high-fidelity color reproduction, but for ordinary PC users seeking better picture quality.
Some high-end LCD monitors use a 3D-LUT, which takes the LUT concept even further. A traditional LUT system has one LUT for each RGB color and refers to the LUT for each RGB color when displaying a certain color and calculating the target color using the three RGB colors from each LUT.
In contrast, a 3D-LUT is a three-dimensional LUT blending each RGB color (i.e., a three-dimensional table assigning R, G, and B to each of three axes). Since the LUT includes points of intermediate gradations blending R, G, and B, it offers improved color representation for intermediate gradations and improved gray-scale accuracy.
Let"s use EIZO"s widescreen LCD monitors as examples. Model CG242W in the ColorEdge series features a 3D-LUT. The difference between theoretical values and actual measured values in intermediate gradations is smaller than with traditional LUTs.
3D-LUTs also shine when converting color gamuts in a color-management environment. They make it possible to reallocate the approximately 16.77 million colors allocated to one color gamut to another color gamut with high precision, minimizing the loss of information from the original color gamut. In addition, since the 3D-LUT offers improved color reproduction from RGB blending, the user"s manipulations and color adjustments generally have the expected results with respect to parameters such as brightness, chroma, and hue. Perhaps this is the most important aspect of performance for an LCD monitor used in color management, which above all else requires accurate color reproduction.
The number of bits at which the LCD panel operates, its LUT, and the precision of the internal calculations all significantly affect the color reproduction capabilities of an LCD monitor. In not a few cases, even products with specs that look similar at first glance can diverge unexpectedly in display tendencies. Assessing monitor picture quality from catalog specs alone is unrealistic; users should inspect an actual monitor unit with their own eyes before purchasing.
LCD Monitor Course II, which kicks off this session, will address certain points one must know to choose the LCD monitor best-suited to one"s needs from the various models available. Part 1 will focus on color gamut. While wide color gamuts are the latest trend in LCD monitors, color gamut is a term that lends itself to misunderstanding. Our hope is that this session will help users better understand the color gamut of LCD monitors and better select, use, and adjust the products.
Note: Below is the translation from the Japanese of the ITmedia article "IT Media LCD Monitor Course II, Part 1" published on November 11, 2008. Copyright 2011 ITmedia Inc. All Rights Reserved.
A color gamut defines a more specific range of colors from the range of colors identifiable by the human eye (i.e., the visible spectrum). While color imaging devices include a wide range of devices, such as digital cameras, scanners, monitors, and printers, since the range of colors they can reproduce varies, the color gamut is established to make these differences clear and to reconcile the colors that can be used in common between devices.
Various methods are used to express (diagram) the color gamut, but the common method used for display products is the xy chromaticity diagram of the XYZ color system established by the International Commission on Illumination (CIE). In an xy chromaticity diagram, the colors of the visible range are represented using numerical figures and graphed as color coordinates. In the following xy chromaticity diagram, the area shaped like an upside-down "U" surrounded by dotted lines indicates the range of colors visible to human beings with the naked eye.
Various standards govern color gamuts. The three standards frequently cited in relation to personal computers are sRGB, Adobe RGB, and NTSC. The color gamut defined by each standard is depicted as a triangle on the xy chromaticity diagram. These triangles show the peak RGB coordinates connected by straight lines. A larger area inside a triangle is regarded to represent a standard capable of displaying more colors. For LCD monitors, this means that a product compatible with a color gamut associated with a larger triangle can reproduce a wider range of colors on screen.
This is a CIE XYZ color system xy chromaticity diagram. The areas enclosed in dotted lines represent the range of colors human beings can see with the naked eye. The ranges corresponding to the sRGB, Adobe RGB, and NTSC standards defining color gamuts appear as triangles connecting their RGB peak coordinates. The color gamut of an LCD monitor"s hardware can be indicated using similar triangles. An LCD monitor is not capable of reproduction (display) of colors outside its color gamut.
The standard color gamut for personal computers is the international sRGB standard prepared in 1998 by the International Electrotechnical Commission (IEC). sRGB has established a firm position as the standard in Windows environments. In most cases, products like LCD monitors, printers, digital cameras, and various applications are configured to reproduce the sRGB color gamut as accurately as possible. By ensuring that the devices and applications used in the input and output of image data are sRGB compatible, we can reduce discrepancies in color between input and output.
However, a look at the xy chromaticity diagram shows that the range of colors that can be expressed using sRGB is narrow. In particular, sRGB excludes the range of highly saturated colors. For this reason, as well as the fact that advances in devices such as digital cameras and printers have led to widespread use of devices capable of reproducing colors more vivid than those allowed under the sRGB standard, the Adobe RGB standard and its wider color gamut have recently drawn interest. Adobe RGB is characterized by a broader range than sRGB, particularly in the G domain—that is, by its ability to express more vivid greens.
Adobe RGB was defined in 1998 by Adobe Systems, maker of the well-known Photoshop series of photo-retouching software products. While not an international standard like sRGB, it has become— backed by the high market share of Adobe"s graphics applications—the de facto standard in professional color imaging environments and in the print and publishing industries. Growing numbers of LCD monitors can reproduce most of the Adobe RGB color gamut.
NTSC, the color-gamut standard for analog television, is a color gamut developed by the National Television Standards Committee of the United States. While the range of colors that can be depicted under the NTSC standard is close to that of Adobe RGB, its R and B values differ slightly. The sRGB color gamut covers about 72% of the NTSC gamut. While monitors capable of reproducing the NTSC color gamut are required in places like video production sites, this is less important for individual users or for applications involving still images. sRGB compatibility and the capacity to reproduce the Adobe RGB color gamut are key points of LCD monitors that handle still images.
The visual differences between Adobe RGB (photo at left) and sRGB (photo at right). Converting a photograph in the Adobe RGB color gamut to the sRGB domain results in the loss of highly saturated color data and loss of tonal subtleties (i.e., a susceptibility to color saturation and tone jumping). The Adobe RGB color gamut can reproduce more highly saturated colors than sRGB color. (Note that the actual colors displayed will vary with factors such as the monitor used to view them and the software environment. The sample photographs should be used for reference only.)
In general, the LCD monitors currently available for use with PCs have color gamuts capable of displaying nearly the entire sRGB gamut, thanks to the specifications for their LCD panels (and panel controls). However, given the rising demand mentioned above for reproducing color gamuts broader than sRGB, recent models have expanded the color gamuts of LCD monitors, with Adobe RGB serving as one target. But how is such expansion of LCD monitor color gamuts taking place?
Improvements in backlights account for a significant proportion of the technologies expanding the color gamuts of LCD monitors. There are two major approaches to doing this: one involves expanding the color gamut of cold cathodes, the mainstream backlight technology; the other involves RGB LED backlights.
On the subject of color-gamut expansion using cold cathodes, while strengthening the LCD panel"s color filter is a quick fix, this also lowers screen luminance by decreasing light transmissivity. Increasing the luminance of the cold cathode to counter this effect tends to shorten the life of the device and often results in lighting irregularities. Efforts to date have overcome these drawbacks to a large extent; many LCD monitors feature cold cathodes with wide color gamuts resulting from modification of their phosphors. This generates cost benefits as well, since it makes it possible to expand the color gamut without major changes in the existing structure.
Use of RGB LED backlights has increased relatively recently. These backlights make it possible to achieve higher levels of luminance and purity of color than cold cathodes. Despite certain disadvantages, including lower color stability (i.e., radiant-heat problems) than a cold cathode and difficulty in attaining a uniform white color across the entire screen, since it involves a mixture of RGB LEDs, these weaknesses have been resolved for the most part. RGB LED backlights cost more than cold-cathode backlights and are currently used in a fairly small proportion of LCD monitors. However, based on their efficacy in expanding color gamuts, the number of LCD monitors incorporating the technology will likely increase. This is also true for LCD televisions.
In passing, many LCD monitors that extol wide color gamuts promote the area ratios of specific color gamuts (i.e., triangles on the xy chromaticity diagram). Many of us have probably have seen indications of attributes such as Adobe RGB rates and NTSC rates in product catalogs.
However, these are only area ratios. Very few products include the entire Adobe RGB and NTSC color gamuts. Even if a monitor featured a 120% Adobe RGB ratio, it would remain impossible to determine the extent of the difference in RGB values between the LCD monitor"s color gamut and the Adobe RGB color gamut. Since such statements lend themselves to misinterpretation, it is important to avoid being confused by product specifications.
To eliminate problems involving labeled specifications, some manufacturers use the expression "coverage" in place of "area." Clearly, for example, an LCD monitor labeled as having Adobe RGB coverage of 95% can reproduce 95% of the Adobe RGB color gamut.
From the user"s perspective, coverage is a more user-friendly, easier-to-understand type of labeling than surface ratio. While switching all labeling to coverage presents difficulties, showing in xy chromaticity diagrams the color gamuts of LCD monitors to be used in color management will certainly make it easier for users to form their own judgments.
With regard to the difference between area labeling and coverage labeling as gauges of an LCD monitor"s color gamut, to use Adobe RGB as an example, in many cases, even a monitor with an Adobe RGB ratio of 100% in terms of area will feature coverage of less than 100 percent. Since coverage impacts practical use, one must avoid the mistake of seeing a higher figure as automatically better.
When we check the color gamut of an LCD monitor, it"s also important to remember that a wide color gamut is not necessarily equivalent to high image quality. This point may generate misunderstanding among many people.
Color gamut is one spec used to measure the image quality of an LCD monitor, but color gamut alone does not determine image quality. The quality of the controls used to realize the full capabilities of an LCD panel having a wide color gamut is crucial. In essence, the capacity to generate accurate colors suited to one"s own purposes outweighs a wide color gamut.
When considering an LCD monitor with a wide color gamut, we need to determine if it has a color-gamut conversion function. Such functions control the LCD monitor"s color gamut based on the target color gamut, such as Adobe RGB or sRGB. For example, by selecting sRGB mode from a menu option, we can adjust even an LCD monitor with a wide color gamut and high Adobe RGB coverage so that the colors displayed on screen fall within the sRGB color gamut.
Few current LCD monitors offer color-gamut conversion functions (i.e., feature compatibility with both Adobe RGB and sRGB color gamuts). However, a color-gamut conversion function is essential for applications demanding accurate color generation in the Adobe RGB and sRGB color gamuts, such as photo retouching and Web production.
For purposes requiring accurate color generation, an LCD color monitor lacking any color-gamut conversion function but having a wide color gamut can actually be a disadvantage in some cases. These LCD monitors display each RGB color mapped to the color gamut inherent to the LCD panel in eight bits at full color. As a result, the colors generated are often too vivid for displaying images in the sRGB color gamut (i.e., the sRGB color gamut cannot be reproduced accurately).
Shown here are examples of an sRGB color gamut photograph displayed on an sRGB-compatible LCD monitor (photo at left) and on an LCD monitor with a wide color gamut but incompatible with sRGB and with no color-gamut conversion function (photo at right). While the photograph at right appears vivid, saturation is unnaturally high in parts of the photo. We also see a significant departure from the colors envisioned by the photographer, as well as so-called memory colors.
In more than a few cases, as expanding LCD monitor color gamuts result in the capacity to reproduce a wider range of colors and more opportunities to check colors or adjusting images on monitor screens, problems such as breakdowns in tonal gradations, variations in chromaticity caused by narrow viewing angles, and screen display irregularities, less conspicuous at color gamuts in the sRGB range, have become more pronounced. As mentioned earlier, the mere fact of incorporating an LCD panel with a wide color gamut does not ensure that an LCD monitor offers high image quality. On this subject, let"s take a close look at various technologies for putting a wide color gamut to use.
First we look at technologies to increase gradation. Key here is the internal gamma-correction function for multi-level gradation. This function displays eight-bit input signals on screen in each RGB color from the PC side after first subjecting them to multi-level gradation to 10 or more bits in each RGB color inside the LCD monitor, then assigning these to each RGB eight-bit color deemed optimal. This improves tonal gradations and gaps in hue by improving the gamma curve.
On the subject of the viewing angle of an LCD panel, while larger screen sizes generally make it easier to see differences, particularly with products with wide color gamuts, variations in chromaticity can be an issue. For the most part, chromaticity variation due to viewing angle is determined by the technology of the LCD panel, with superior ones showing no variation in color even when viewed from a moderate angle. Setting aside the various particulars of LCD panel technologies, these generally include in-plane switching (IPS), vertical alignment (VA), and twisted nematic (TN) panels, listed from smaller to larger chromaticity variation. While TN technology has advanced to the point at which viewing angle characteristics are much improved from several years back, a significant gap remains between this technology and VA and IPS technologies. If color performance and chromaticity variation are important, VA or IPS technology remains the better choice.
A uniformity-correction function is a technology for reducing display irregularities. The uniformity referred to here refers to colors and brightness (luminance) on screen. An LCD monitor with superior uniformity has low levels of screen luminance irregularities or color irregularities. High-performance LCD monitors feature systems that measure luminance and chromaticity at each position on screen and correct them internally.
This is a comparison of monitors with and without uniformity correction. An LCD monitor with uniformity correction (photo at left) has more uniform luminance and color on screen than one lacking uniformity correction (photo at right). The two photographs above have been adjusted to equalize levels to emphasize display irregularities. Actual irregularities would be less conspicuous.
To make full use of an LCD monitor with a wide color gamut and to display colors as the user intended, one needs to consider adopting a calibration environment. LCD monitor calibration is a system for measuring colors on screen using a special-purpose calibrator and reflecting the characteristics of the colors in the ICC profile (a file defining device color characteristics) used by the operating system. Going through an ICC profile ensures uniformity between the color information handled by graphics software or other software and the colors generated by the LCD monitor to a high degree of precision.
Software calibration refers to following the instructions of specialized calibration software to adjust parameters such as luminance, contrast, and color temperature (RGB balance) using the LCD monitor"s adjustment menu, approaching the intended color through manual adjustments. Graphics driver colors are manipulated in some cases in place of the LCD monitor"s adjustment menu. Software calibration features low cost and can be used to calibrate any LCD monitor.
However, variations in precision can arise since software calibration involves manual adjustment. Internally, RGB gradation can suffer because display balance is matched by thinning RGB output levels using software processing. Even so, use of software calibration will likely make it easier to reproduce colors as intended than using no calibration at all.
In contrast, hardware calibration is clearly more precise than software calibration. It also requires less effort, although it can be used only with compatible LCD monitors and entails certain setup costs. In general, it involves the following steps: calibration software controls the calibrator; matching color characteristics on screen with target color characteristics and directly adjusting the LCD monitor"s luminance, contrast, and gamma-correction table (look-up table) at the hardware level. Another aspect of hardware calibration that cannot be overlooked is its ease of use. All tasks through the preparation of an ICC profile for the results of adjustment and registering this to the OS are done automatically.
The EIZO LCD monitors currently compatible with hardware calibration include models in the ColorEdge series. The FlexScan series uses software calibration. (Note: As of January 2011, FlexScan monitors compatible with EasyPIX ver. 2 offer hardware calibration functionality.)
By combining a ColorEdge-series monitor with a calibrator and ColorNavigator special-purpose color-calibration software, one can achieve easy, precise hardware calibration.
In the next session, we will examine LCD monitor interfaces and a number of video interfaces for LCD monitors, including the latest generation of interfaces such as HDMI and DisplayPort.
I recently replaced the LCD on my iPhone 5s, so far i did not have any problems. Recently i noticed that when using my phone in the night or dark hours my lcd drastically increases on a gray fade. I"ve tried to switch display accommodations off as well as used the night shift feature, but the problem persists. I"m sure i have installed the lcd properly since there is no lag on touch response, no marks on screen of applied pressure, and no halo or color distortion. All my blacks turn to gray and this is mostly during night times, is something wrong with my screen lcd?
Programming the screen is needed for the light sensor and true tone functionality to work and so many people/repair businesses fail to do so. Do you see any text that says “True Tone” found in settings < display and brightness?
FSC LCD’sare a uniquely different color technology. They are not a replacement for OLED’s or TFT’s because they do not display video or high resolution photos.
Henry Ford meets Burger King -When Henry Ford built his first car, he told his customers they could have any color car they wanted as long as it was black. Car manufacturers now offer multiple options to their consumers. The customer can choose their paint color, interior color, automatic or manual transmission, even heated seats.
In the past, OEM designers were restricted to standard size color displays set by the OLED or TFT manufacturer. FSC technology removes this constraint and at a surprisingly low cost.
FSC color displays take the single color offered by static/segmented display and add seven additional colors. The attached Youtube link shows a video of the display as it changes colors. (
How does this new technology work? FSC LCD Displays implement an RGB backlight to display brilliant bright colors. The colors are brighter then other displays because there is no filter.
The lack of filter allows a darker black positive mode (dark letters on a light background) and a brighter white negative mode (light colored letters on a dark background)..
Five steps to your own custom color LCD display moduleCreate a drawing that includes the size of the glass,the icons and segments you want. The icons and segments can be placed on the drawing to show an approximate location. Here is a link to our engineering support page. Call us if you need support with your designs.
After you submit your drawing, you will recevie a counter drawing (A cad drawing showing the exact dimensions of the display) within three to five business days.
What is the difference between a FSC color display and a segmet/static display?The FSC display provides seven colors plus the background color. The static display only offers one color.
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.
The origins and the complex history of liquid-crystal displays from the perspective of an insider during the early days were described by Joseph A. Castellano in Liquid Gold: The Story of Liquid Crystal Displays and the Creation of an Industry.IEEE History Center.Peter J. Wild, can be found at the Engineering and Technology History Wiki.
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,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.
Displays having a passive-matrix structure are employing Crosstalk between activated and non-activated pixels has to be handled properly by keeping the RMS voltage of non-activated pixels below the threshold voltage as discovered by Peter J. Wild in 1972,
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.
Twisted nematic displays contain liquid crystals that twist and untwist at varying degrees to allow light to pass through. When no voltage is applied to a TN liquid crystal cell, polarized light passes through the 90-degrees twisted LC layer. In proportion to the voltage applied, the liquid crystals untwist changing the polarization and blocking the light"s path. By properly adjusting the le