lcd panel layers supplier

Ever wondered how devices display graphics and text on their screen? It’s the work of a graphic LCD module. An electronic visual display technology, a graphic LCD implements tiny crystals made from a liquid-crystal solution. The tiny crystals are manipulated to create images on a two-dimensional screen by producing accurate electronic signals.

That is how a graphic LCD works, but there’s more to it than that, and it’s important to understand how this technology works for you to utilize it properly in the manufacture of devices.

A graphic LCD has five basic layers that are parallel to each other. The first and second layers are responsible for transforming and changing light signals’ polarization to create images. Once the signals are polarized and hit the third layer, the technology is able to determine the required color and shape of the image that will be displayed. This third layer will then bring the constructed shape to the fourth layer, which utilizes a liquid crystal solution to make the image more distinct. It’s in the fifth layer where the image is completely polarized and shown through its glass or plastic screen.

Ordinary users may not know it, but graphic LCDs are almost everywhere–most commonly, in cell phone and laptop screens. They’re also used in calculators, electronic watches, and digital readers. Flat-screen televisions also utilize it, as well as medical gadgets and appliances. Thanks to continuing advancements, graphic LCDs are starting to receive enhanced design and operational assembly allowing them to process inputs by users such as text, sound, or artwork and produce the corresponding output.

Many manufacturers use a graphic LCD because of its advantages over traditional CRT-based visual display units. One key advantage lies in its thin, compact dimensions and lighter weight, allowing it to be used in portable electronic devices. It shows a detailed display of three-dimensional images as well. It also consumes less power, making it more energy efficient.

When it comes to creating and displaying images and text on an LCD display module, you can turn to a graphic LCD. Understanding how this technology functions is essential to your production. If you’re still not sure how to utilize it properly for your business, you can always obtain expert advice from a supplier of graphic LCDs. They can help you make the best choice.

We all spend hours looking at LCDs at home and at work as well as on our boats. But how many of us know how they work or—more importantly—how to choose a good one? Equipment manufacturers bombard us with snippets of information, but what does it all mean? Is a QVGA better or worse than WXGA? Just how big is a nit? And is CCFL on its way in or out?ADVERTISEMENTThanks for watching!Visit Website

To start at the beginning, LCD stands for Liquid Crystal Display, a high-tech sandwich with a layer of liquid crystals at its heart. But just as it takes more than beef to make a burger, it takes more than liquid crystals to make a display.

A very simple LCD is made up of seven layers. (See illustration below.) At the back of the screen is a layer of film that polarizes the light from the display backlighting so that all the electromagnetic waves that make up light are going in the same direction. Then comes a glass filter etched with a pattern of ridges and furrows, like a plowed field but reduced to molecular scale. Then comes one of the electrodes that will apply a voltage to the liquid crystal.

Four layers in, we come to the liquid crystal itself, before repeating the original three layers in the opposite order, but with one crucial difference: In the inner layers, the furrows in the filter are lined up with the polarizing film. In the outer layers the film and furrows are also lined up with each other but are rotated 90 degrees from those in the inner layer.

Any experienced boater has undoubtedly owned a pair of polarized sunglasses and so can probably appreciate how light can pass through two pieces of polarized film as long as they’re polarized in the same direction but is blocked if you rotate one of the films through 90 degrees. So our LCD sandwich would be opaque if it were not for the liquid crystal’s ability to change the polarization of light. The tiny furrows in the glass filters force the molecules of the liquid crystal to arrange themselves in a twisted pattern, so that they twist the polarization of the light that passes through them—allowing it to pass straight through the whole sandwich. But when an electrical voltage is applied to the liquid crystal layer, it overrides the twisted structure of the liquid crystal and forces the molecules to line up with each other. In this situation, the polarized light no longer twists as it is passed through the liquid crystal, so the sandwich becomes opaque.

Controlling such huge numbers of pixels and subpixels would be completely impossible if screen makers were still using the grids of wires that controlled the simple LCDs of the ‘70s. What made modern displays possible was a development known as Thin Film Transistors (TFTs) in which thousands of tiny transistors can be built into a thin transparent film and used as miniature switches to control the individual pixels of the display. It’s thanks to TFTs that we saw a sudden shift from the crude, blocky, monochrome displays of the ‘70s and ‘80s to the much higher-definition color displays of the late ‘90s.

When you stop and think about what goes into displaying one of these amazing images, you might recognize most are protected by a glass cover. You might even be familiar with display types like LCD or OLED. Yet for many, the recognition stops there. You may see the image on the surface, but rarely think about what creates that image, how it achieves life-like, vibrant color, and the journey it makes to reach our eyes.

If we look deeper, beyond the surface and the cover glass of our devices, we would find one or more layers of ultra-thin, technical glass make such images possible. Each layer with a different purpose, all working together to deliver the beautiful, thin displays we use each and every day. Combined, these layers form what we at Corning call the “glass stack.”

It’s worth looking at the individual layers of the glass stack, since each layer is the result of breakthroughs in glass science, optical physics, and state of the art manufacturing. At the top of the stack, we have the protective cover glass of a mobile device that most consumers have heard of – Corning Gorilla Glass. This cover glass protects and maintains the appearance of the display, and also supports the use of front-facing cameras and various sensors. Often, the rear side of such devices is covered with a similar protective glass, which also allows for wireless charging.

Though each layer of the glass stack is formed with the same fusion manufacturing process, the compositions of the glass are different – allowing for different properties and benefits. LCD and OLED displays, whether on mobile devices with glass cover and back or otherwise, utilize different super-thin layers of glass specific to their applications:

Computer monitor is one component of the computer hardware that digital photography enthusiasts, regardless of being amateurs, serious hobbyists, or graphic designers interact with on a daily basis. Whether it is the Liquid Crystal Display (LCD) or the Cathode Ray Tube (CRT) is much less important today than it was several years ago - and I do not intend to argue for one over the other. Suffice to say that the trend of many companies has been to cut production of CRT monitors. Hence the LCD flat screen monitors are quickly becoming a new standard in many computing environments.

Since these pages are dedicated to color and color management, the following sections will detail elements of LCD displays that have a major impact on the overall color performance.

Most of the LCD displays today use a series of fluorescent lamps at the back (sometimes at the top) of the panel. Backlight fluorescent lamps (mostly CCFL

Composition of phosphors in not necessarily the same for all monitors. The following animated gifs exemplify CRT (Fig. 2) and LCD (Fig. 3) displays and their spectral radiance characteristics measured by the EyeOne Pro spectrophotometer.

Unfortunately, with resolution of this device being around 10 nm, overlap of spectral peaks will occur. While wider and poorly resolved bands are observed, the qualitative differences are still easy to spot. First snapshot shows the spectral radiance distribution for a white (RGB = 255, 255, 255). It is apparent that the fluorescent lamp source has narrower line-shapes with maximum emission in green region of the spectrum. The CRT phosphors are clearly broader and the red component has two distinct peaks. Comparison of the green regions of CRT and LCD monitors (530-560 nm) would suggest extended gamut for the LCD display as the green band there is narrower.

This is indeed the case as we will see later (Figure 4). Next frame set shows the spectral distribution at the black level (R=G=B=0). The non-zero radiances just underline the fact that there is no real black in either of the display type. The spectral distribution of the "black" is similar to that of the white, with some more energy emitted in the blue region of the spectrum. Subsequent three frames illustrate the spectral radiance distributions of the separate RGB primaries for both displays. LCD display with included broadband RGB filters features more narrow-band regions while rather large spectral widths are seen in blue and green channels of the CRT

display. Figure 4 shows a comparison of typical gamuts of LCD (meshed) and CRT (green) monitors. While gamut volumes are about the same, the CRT has an edge in the less saturated blue-magenta areas (point A). On the other hand, the LCD has more saturated blues and red-orange-yellow areas (point B). However, due to the spectral impurities affecting both types of monitors, gamuts of CCFL based LCD displays as well as CRTs are relatively limited and close to sRGB color space (Fig. 6). Position and size of the sRGB triangle clearly shows that there are significant rendering limitations of these display devices. Particularly large are areas in the green portion of the CIE 1931 (x, y)-chromaticity diagram. It has been shown that the human visual system can distinguish between colors differing by about 1 nm in the blue-yellow region, but near the visible spectrum boundaries a 10-nm separation is required (Pointer 1998).

Size of the gamut and the extent to what a typical LCD monitor differs from the standard sRGB gamut are shown in the CIE 1931 (x, y)-chromaticity diagrams (Figure 6). In this case, the Eizo CG19 monitor was calibrated with the Eye1 Pro spectrophotometer. Eizo"s Color Navigator (top image) and its gamut boundaries were compared with GretagMacbeth"s iMatch3 (toggle images by pointing your mouse over the image). 3-D gamut volumes for both

profiles are about 106% of the sRGB color space. In both cases, the area of displayed colors extends toward the cyan-green region outside of the sRGB gamut. At the same time, magenta and saturated darker blues are slightly compromised when compared to the sRGB gamut. Nearly identical gamut and spectral data for the Eizo CG19 monitor were obtained by Hoffmann p.36. Recently, LCD monitors having backlight lamps with improved phosphors appeared on the market (e.g. Samsung SyncMaster 931C or 226CW). Gamut of those monitors extends far beyond the limits of the standard sRGB color space - more towards green tones by sacrificing some yellow. Red and blue primaries stay about the same. To increase the display gamut to e.g., Adobe RGB color space, new types of phosphors or much purer and narrower RGB light sources are required.

The emergence of light emitting diodes (LEDs) bright enough to backlight LCD displays already shows significant enhancements in color saturation which translates into wider gamut. At this time, Eizo (CG220 line), NEC (SpectraView 2690wuxi), Samsung (SyncMaster XL20) and others already commercialize higher end wide gamut (Adobe RGB, NTSC) LCD displays. Read more about LED backlighting of LCD panels.

Last point in this section is a brief discussion on the lightness homogeneity. The white diffusion panel behind the LCD layer redirects and scatters the light evenly to ensure uniform display properties. Imperfections in design of diffusion panels lead to uneven illumination and light seepage often seen in low and middle end LCD displays. Situation is even more challenging for the LED based light sources where fixed location of RGB emitting diodes makes it difficult to produce evenly dispersed white light. That is why an uneven display brightness can be seen in older or less expensive displays.

Finally we come to the heart of the LCD display technology - liquid crystals. Simply put, liquid crystals are organic molecules that, within certain temperature range, exhibit fluid characteristics of a liquid and the molecular orientation order of solid states. In terms of shape, liquid crystals usually consist of "rod-like" molecules which tend to align themselves with the applied electrical field. There has been a considerable progress made over the past 30 years in the development of low-molecular-weight liquid crystals. In typical LCDs today, liquid crystals are present in a form of a 5-6 μm thick film in amounts of only 0.5-0.6 ug of liquid crystals per square centimeter (0.5 mg in a 19-inch monitor). In order to attain optimal performance of any LCD screen, liquid crystal materials have to meet certain physico-chemical properties. These include optimal nematic phase range (-40o to 100oC), clearing point,

The cholesteric (or chiral nematic) liquid crystal phase is typically composed of nematic molecules containing a chiral center. This leads to the formation of optically active helical structures which can be visualized as a stack of very thin 2-D nematic-like layers with the director in each layer rotated with respect to those above and below.

Nematic liquid crystals are commonly found in LCD displays and their molecular orientation (and hence the optical properties) can be controlled with applied electric fields.

Figure 7 illustrates the principle behind the typical twisted nematic (TN) liquid crystal display. A display using active matrix TFT technology (most of today"s displays) is an LCD that has a separate and independent transistor for each RGB subpixel on the display.

Having a transistor at each subpixel means that the current that triggers pixel illumination can be smaller and therefore it may be switched on and off more quickly. The main components (as mentioned above) are the glass substrate covered by a transparent indium-tin oxide (ITO) electrode layer, polarizing filters, birefringent compensator films, and color filters. In a TN-LCD type, liquid crystals form a 90-degree twisted helix sandwiched between two polarizing filters (a and b). The orientation of the liquid crystals is achieved by an alignment layer of directionally rubbed polyimine layer just above electrodes. Unpolarized light from the backlight fluorescent lamp is plane polarized by the rear polarizer a. When no voltage is applied (off-state), the light passes as the liquid crystals rotate the polarization plane to match polarization plane of the lower filter (left drawing); when a voltage is applied, helical arrangement of LCs is disrupted, light is absorbed by the front polarizer b (hence effectively blocked) and the screen appears black (right drawing). Also, in the off-state, the angle between the longer molecular axis and the plane of alignment layer varies with intracellular distance. This results in a narrow viewing angle. Effect of on/off switching of LCD crystals is similar to the opposite rotation of two elements of any circular polarizing filter. In this case though, it is the polarizing planes (such as a and b) that change to cause darkening or lightening of the image seen through it.

A grouping of red, green and blue subpixels defines the composite color that the pixel transmits. There is only a limited variety of dyes and pigments compatible with LCD technology. Thus spectral transmission can only be tweaked up to certain limits by changing thickness and dye concentration of the color filter.

In Figure 8, chemical structures of the most typical molecules used in desktop displays are shown. Historically, 5CB ( I ) was the first member of the optically and chemically stable cyanobiphenyls introduced on the market (discovered in 1973). It has been one of the most applicable family of liquid crystals. Since the early 1980s, new class of liquid crystals containing carbon-fluorine bonds has been used in TN-TFT-LCD displays. To maintain the strong dielectric anisotropy, perfluoroalkyl chains had to be incorporated in those molecules to compensate for removal of the nitrile group (e.g. II). Basis of so called in-plane switching panels (IPS) is the molecular reorientation that takes place in a plane parallel to the glass substrates (see below). Since higher Δe is needed to compensate for larger electrode distance (intrinsic feature of this technology), IPS-based displays use molecules of type III. Recently, LCDs based on dielectrically negative liquid crystals were introduced to the market. Placing fluorine substituents at positions 2- and 3- of the aromatic ring leads to cancellation of the dipole moment component in the direction of the long molecular axis (IV).

This causes molecules to orient perpendicular to the applied electric field (as opposed to the parallel orientation when Δe is positive). The corresponding LCD panels feature high contrast and wide viewing angle. Computer generated models of core substructures of fluorinated molecules (II and IV) with electrostatic potential (ESP) encoded on the molecule"s electron density surface are shown in Figure 9. Red areas represent a negative electrostatic potential (increased electron density) and blue represents a positive ESP. Orientation and size of the molecular dipole moment can be easily predicted even low level theoretical models. Note the orthogonal direction of the dipole moment vectors for dielectrically positive (II) and dielectrically negative (IV) molecules. Arrows point to direction of increased electron density. Such molecules can be easily and quickly manipulated in fast switching electric fields.

The IPS (In-Plane Switching) technology was developed by Hitachi in 1996 to address two limitations of TN-matrices: small viewing angles and low-quality color reproduction. The name comes from the crystals in the cells of the IPS panel lying always in the same plane and being always parallel to the panel"s plane (Figure 10). When voltage is applied to a cell, the crystals of that cell all make a 90-degrees turn.

In this arrangement, an IPS panel lets the backlight pass through in its active state and shutters it in its passive state (when no voltage is applied), so if a thin-film transistor breaks, the corresponding "dead" pixel will always remain black (unlike with TN matrices). IPS matrices differ from TN ones not only in the spatial arrangement of the crystals, but also in the placement of the electrodes - both electrodes are on one wafer and take more space than electrodes of TN matrices. This unfortunately leads to a lower contrast and brightness of the matrix.

Over the years, the original IPS technology evolved into several significant improvements: Super-IPS (S-IPS), Dual Domain IPS (DD-IPS), and Advanced Coplanar Electrode (ACE). The IPS technology has always been better than TN+Film in terms of color reproduction and viewing angles. S-IPS matrices have soft and pleasant colors, which are natural and close to high-quality CRT monitors. That"s why nearly all LCD monitors for professional work with color are based on S-IPS matrices. They range from relatively inexpensive to hi-end models of the Eizo ColorEdge series with integrated tools for custom hardware color-calibration. The viewing angles are excellent. Unfortunately, there is one specific weakness - when looking at the screen from a side, shadows have a characteristic violet hue. The only real limitation of the S-IPS technology is relatively low contrast ratio.

Brightness refers to the luminance of white color emitted on screen and is measured in candela per square meter (cd/m2 - same as the older unit "nit"). The higher the numbers are, the brighter the screen will be. Contrast (or better contrast ratio) is the luminance ratio (unit of 1) of white to black levels. It is expressed in the form of e.g. "400:1" and simply represents the relative brightness ratio of the "white" to "black". It is the contrast that is often cited as the "notorious" weaknesses of LCD matrices. As explained earlier, LCD matrix is passive rather than active element and as such, it can"t radiate any light. Instead, it can only modulate the light that is passing through it. Due to various reasons related to the quality of polarizing panels and liquid crystals themselves, the light coming from a backlight source cannot be completely stopped. Hence some portion of the backlight will pass through the matrix causing the shadows never being black (Y > 0.3 cd/m2). The fact that a good CRT monitor provides better contrast than a good LCD monitor is the consequence of LCD matrix design principle.

and CONTRAST. Note that these controls have different functions than controls (of the same name) on a CRT display! In the LCD world, the BRIGHTNESS control alters the backlight luminance effecting what in a CRT would be CONTRAST. Sometimes video card or monitor lookup tables (LUTs) are used in addition to set the desired brightness. If you read that contrast sets the overall brightness and brightness actually sets contrast then the reference is to the CRT monitors. In LCD displays, BRIGHTNESS changes both black and while levels at the same time (Fig. 11) while CONTRAST adjusts the brightness of while levels, keeping black levels unchanged (Fig. 12). Moreover, LCD displays do not have the real contrast control. Contrast is set by adjusting video signal in the video card. It should be noted that reduction in contrast reduces the display dynamic range whereas a reduction of brightness (if it is done with the lamps) does not. That’s why it is always preferable to achieve the best-looking image using the brightness setting (O. Artamonov in X-bit labs reviews).

Industrial LCD (liquid crystal display) monitors are a common technological fixture for a variety of Marine, military, and even commercial applications. These monitors have internal mechanisms that allow them to display specific images according to the user’s commands. In order for the screen to work, all of the internal components that make up the mechanism must function at full capacity. Liquid crystals are the main components that contribute to the picture quality, sharpness, and brightness, but there are also other crucial elements at play inside each screen.

Every computer screen has an LED backlight that produces white light. The light then travels through many different layers to produce an image on the screen. Flat panel displays feature LED backlights because they reduce overheating, have higher contrast ratios, more extensive brightness settings, and excellent overall colour reproduction.

In order for a screen to function properly and display crystal clear images without interruption, every single pixel needs to be charged with an electric current. Transparent conductive screen layers made from materials like indium allow the electric currents to pass through with ease.

The light guide plate is a weather-resistant transparent corrugated stiff plastic panel that controls the angle and direction in which light is displayed. As the light enters the back of the panel, the pattern formed by the ridges on the front guides it into different directions to illuminate the pixels and form the images that appear on the screen.

LCD monitors feature two polarized glass sheets that function as filters that make it possible for users to clearly view images on the screen. The liquid crystals are located between the two layers of polarizing sheets. Essentially, polarizers allow vertical light waves to pass through the filter and contact the light bending liquid crystals. Horizontal light waves are blocked or filtered out because they distort the image quality. Since they’re made of a plastic-like material, polarizers are sensitive to extremely humid and hot temperature conditions.

Backplanes are typically used in thin-film transistor (TFT) LCD monitors. Located toward the front of the screen, this glass substrate displays the images that result from the dual polarization process to the end-user.

Modern LCD monitors use a material called indium-tin-oxide, which acts as the main power source for the entire screen and its light-emitting functions. This common electrode sends required voltage levels to activate and manipulate the liquid crystals. Most of the white light produced by the backlight is blocked out and colour filters are used to create crystal clear images on the screen. Colour filters consist of the primary colours red, blue, and green.

Nauticomp Inc.is one of the leading North American distributors of military, marine, commercial, and industrial LCD monitors. With 25 years of experience in the technological space, we’ve mastered the art of designing and crafting top-of-the-line digital displays that are custom-tailored to the needs of our customers. Contact ustoday to learn more.

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

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

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

Industrial LCD (liquid crystal display) monitors are a common technological fixture for a variety of Marine, military, and even commercial applications. These monitors have internal mechanisms that allow them to display specific images according to the user’s commands. In order for the screen to work, all of the internal components that make up the mechanism must function at full capacity. Liquid crystals are the main components that contribute to the picture quality, sharpness, and brightness, but there are also other crucial elements at play inside each screen.

Every computer screen has an LED backlight that produces white light. The light then travels through many different layers to produce an image on the screen. Flat panel displays feature LED backlights because they reduce overheating, have higher contrast ratios, more extensive brightness settings, and excellent overall colour reproduction.

In order for a screen to function properly and display crystal clear images without interruption, every single pixel needs to be charged with an electric current. Transparent conductive screen layers made from materials like indium allow the electric currents to pass through with ease.

The light guide plate is a weather-resistant transparent corrugated stiff plastic panel that controls the angle and direction in which light is displayed. As the light enters the back of the panel, the pattern formed by the ridges on the front guides it into different directions to illuminate the pixels and form the images that appear on the screen.

LCD monitors feature two polarized glass sheets that function as filters that make it possible for users to clearly view images on the screen. The liquid crystals are located between the two layers of polarizing sheets. Essentially, polarizers allow vertical light waves to pass through the filter and contact the light bending liquid crystals. Horizontal light waves are blocked or filtered out because they distort the image quality. Since they’re made of a plastic-like material, polarizers are sensitive to extremely humid and hot temperature conditions.

Backplanes are typically used in thin-film transistor (TFT) LCD monitors. Located toward the front of the screen, this glass substrate displays the images that result from the dual polarization process to the end-user.

Modern LCD monitors use a material called indium-tin-oxide, which acts as the main power source for the entire screen and its light-emitting functions. This common electrode sends required voltage levels to activate and manipulate the liquid crystals. Most of the white light produced by the backlight is blocked out and colour filters are used to create crystal clear images on the screen. Colour filters consist of the primary colours red, blue, and green.

Nauticomp Inc.is one of the leading North American distributors of military, marine, commercial, and industrial LCD monitors. With 25 years of experience in the technological space, we’ve mastered the art of designing and crafting top-of-the-line digital displays that are custom-tailored to the needs of our customers. Contact ustoday to learn more.

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

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

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

The most basic LCD introduced above is called passive matrix LCDs which can be found mostly in low end or simple applications like, calculators, utility meters, early time digital watches, alarm clocks etc.  Passive matrix LCDs have a lot of limitations, like the narrow viewing angle, slow response speed, dim, but it is great for power consumption.

In order to improve upon the drawbacks, scientists and engineers developed active matrix LCD technology.  The most widely used is TFT (Thin Film Transistor) LCD technology.  Based on TFT LCD, even more modern LCD technologies are developed. The best known is IPS (In Plane Switching) LCD.  It has super wide viewing angle, superior image picture quality, fast response, great contrast, less burn-in defects etc.

IPS LCDs are widely used in LCD monitors, LCD TVs, Iphone, pads etc. Samsung even revolutionized the LED backlighting to be QLED (quantum dot) to switch off LEDs wherever light is not needed to produce deeper blacks.

– Twisted Nematic Display:  The TN (Twisted Nematic) LCDs production can be done most frequently and used different kinds of displays all over the industries. These displays are most frequently used by gamers as they are cheap & have quick response time as compared with other displays. The main disadvantage of these displays is that they have low quality as well as partial contrast ratios, viewing angles & reproduction of color. But, these devices are sufficient for daily operations.

– In-Plane Switching Display:IPS displays are considered to be the best LCD because they provide good image quality, higher viewing angles, vibrant color precision & difference. These displays are mostly used by graphic designers & in some other applications, LCDs need the maximum potential standards for the reproduction of image & color.

– Vertical Alignment Panel: The vertical alignment (VA) panels drop anywhere in the center among Twisted Nematic and in-plane switching panel technology. These panels have the best viewing angles as well as color reproduction with higher quality features as compared with TN type displays. These panels have a low response time. But, these are much more reasonable and appropriate for daily use.

– The structure of this panel generates deeper blacks as well as better colors as compared with the twisted nematic display. And several crystal alignments can permit for better viewing angles as compared with TN type displays. These displays arrive with a tradeoff because they are expensive as compared with other displays. And also they have slow response times & low refresh rates.

– Advanced Fringe Field Switching (AFFS):  AFFS LCDs offer the best performance & a wide range of color reproduction as compared with IPS displays. The applications of AFFS are very advanced because they can reduce the distortion of color without compromising on the broad viewing angle. Usually, this display is used in highly advanced as well as professional surroundings like in the viable airplane cockpits.

– Passive and Active Matrix Displays: The Passive-matrix type LCDs works with a simple grid so that charge can be supplied to a specific pixel on the LCD. One glass layer gives columns whereas the other one gives rows that are designed by using a clear conductive material like indium-tin-oxide. The passive-matrix system has major drawbacks particularly response time is slow & inaccurate voltage control. The response time of the display mainly refers to the capability of the display to refresh the displayed image.

– Active-matrix type LCDs mainly depend on TFT (thin-film transistors). These transistors are small switching transistors as well as capacitors which are placed within a matrix over a glass substrate. When the proper row is activated then a charge can be transmitted down the exact column so that a specific pixel can be addressed, because all of the additional rows that the column intersects are switched OFF, simply the capacitor next to the designated pixel gets a charge.

LCD technologies have great advantages of light, thin, low power consumption which made wall TVs, laptops, smartphones, pad possible. On its way to progress, it wiped out the competition of many display technologies. We don’t see CRT monitors on our desks and plasma displays TV at our home anymore. LCD Technologies dominant the display market now. But any technology has the limitations.

LCD technologies have slow response times especially at low temperature, limited viewing angles, backlighting is needed. Focus on LCD drawbacks, OLED (Organic Light Emitting Diodes) technology was developed. Some high-end TV and mobile phones start to use AMOLED (Active Matrix Organic Light Emitting Diodes) displays.

This cutting-edge technology provides even better color reproduction, clear image quality, better color gamut, less power consumption when compared to LCD technology. Please note, OLED displays include AMOLED and PMOLED (Passive Matrix Organic Light Emitting Diodes). What you need to choose is AMOLED for your TV and mobile phones instead of PMOLED.

To create an LCD, you take two pieces ofpolarized glass. A special polymer that creates microscopic grooves in the surface is rubbed on the side of the glass that does not have the polarizing film on it. The grooves must be in the same direction as the polarizing film. You then add a coating of nematic liquid crystals to one of the filters. The grooves will cause the first layer of molecules to align with the filter"s orientation. Then add the second piece of glass with the polarizing film at a right angle to the first piece. Each successive layer of TN molecules will gradually twist until the uppermost layer is at a 90-degree angle to the bottom, matching the polarized glass filters.

As light strikes the first filter, it is polarized. The molecules in each layer then guide the light they receive to the next layer. As the light passes through the liquid crystal layers, the molecules also change the light"s plane of vibration to match their own angle. When the light reaches the far side of the liquid crystal substance, it vibrates at the same angle as the final layer of molecules. If the final layer is matched up with the second polarized glass filter, then the light will pass through.

If we apply an electric charge to liquid crystal molecules, they untwist. When they straighten out, they change the angle of the light passing through them so that it no longer matches the angle of the top polarizing filter. Consequently, no light can pass through that area of the LCD, which makes that area darker than the surrounding areas.

Building a simple LCD is easier than you think. Your start with the sandwich of glass and liquid crystals described above and add two transparent electrodes to it. For example, imagine that you want to create the simplest possible LCD with just a single rectangular electrode on it. The layers would look like this:

The LCD needed to do this job is very basic. It has a mirror (A) in back, which makes it reflective. Then, we add a piece of glass (B) with a polarizing film on the bottom side, and a common electrode plane (C) made of indium-tin oxide on top. A common electrode plane covers the entire area of the LCD. Above that is the layer of liquid crystal substance (D). Next comes another piece of glass (E) with an electrode in the shape of the rectangle on the bottom and, on top, another polarizing film (F), at a right angle to the first one.

The electrode is hooked up to a power source like a battery. When there is no current, light entering through the front of the LCD will simply hit the mirror and bounce right back out. But when the battery supplies current to the electrodes, the liquid crystals between the common-plane electrode and the electrode shaped like a rectangle untwist and block the light in that region from passing through. That makes the LCD show the rectangle as a black area.

On the most basic level, most (not all) types of LCDs change the polarization state of light passing through a layer of liquid crystal material. The geometry of that layer is controlled by a competition between boundary conditions and an applied electric field. Usually, for this type of LCD, nematic liquid crystals are used with special coatings applied to the rear and front substrates. The coatings serve to create the boundary conditions and to apply the required electric field. On the outside of the LCD cell, optical films (including polarizer films) are attached. They translate the change in polarization of the light into a bright and dark contrast. The display structure gets assembled in such a way that zero applied field gives one extreme brightness state and fully applied field results in the other extreme. An intermediate field creates an intermediate brightness level.

LCD manufacturers either buy ITO coated glass, or do the ITO coating as part of the manufacturing process. The ITO layer gets defined into shapes and patterns as needed by photolithography. The shapes and patterns of the two ITO layers (front and back) define the pixels and icons on the display.

LCD displays and touch screens are in demand. They offer a sleeker, less cumbersome alternative to a mouse and keyboard or wired touch pad. And since the user can interact directly with the device’s interface, the possibilities for innovation are endless — from elevators and mobile medical equipment to industrial automation.

For many years, electronic device manufacturers generally incorporated five to seven layers of touch screen technology in the manufacture of their products — the LCD panel layers, the touch sensor layer, and the protective top cover or outer glass. Typically a touch screen is mounted on top of the LCD display and either secured with a high-performance double-sided tape, which leaves an air gap, or a silicone gel, called optical bonding, that fills air gaps and enhances readability.

Since 2012, in-cell and on-cell touch screen technologies have taken the high volume consumer segments by storm, in particular, smartphones and tablets. Born out of similar strategies of combining layers for improved functionality, in-cell technology incorporates touch sensors into the actual LCD display panel. On-cell or G2 technology moves the touch sensor to the top cover or outer glass layer.

With fewer layers, in-cell and on-cell touch screens provide designers and engineers the ability to develop much thinner devices, locate touch sensors close to the displays, create better color saturation and visual clarity, and reduce glare. All of which make users feel like they are actually touching the display and not just the outer glass layer.

Fewer layers are beneficial to a manufacturing process as well. It reduces costs by integrating the touch screen sensor as one of the layers of the LCD display, and optical bonding takes place as part of the initial production line, eliminating the need for a secondary bonding process.