raw lcd panel hdmi free sample

A number of people have used a Motorola Atrix Lapdock to add a screen and keyboard with trackpad to RasPi, in essence building a RasPi-based laptop computer. Lapdock is a very clever idea: you plug your Atrix smart phone into Lapdock and it gives you an 11.6" 1366 x 768 HDMI monitor with speakers, a keyboard with trackpad, two USB ports, and a large enough battery for roughly 5 hours of use. The smart phone acts as a motherboard with "good enough" performance. The advantage over a separate laptop or desktop computer is that you have one computing device so you don"t need to transfer files between your phone and your desk/laptop.

Unfortunately for Motorola, Lapdock was not successful (probably because of its US$500 list price) and Motorola discontinued it and sold remaining stock at deep discounts, with many units selling for US$50-100. This makes it a very attractive way to add a modest size HDMI screen to RasPi, with a keyboard/trackpad and rechargeable battery power thrown in for free.

Lapdock has two connectors that plug into an Atrix phone: a Micro HDMI D plug for carrying video and sound, and a Micro USB plug for charging the phone and connecting to the Lapdock"s internal USB hub, which talks to the Lapdock keyboard, trackpad, and two USB ports. With suitable cables and adapters, these two plugs can be connected to RasPi"s full-size HDMI connector and one of RasPi"s full-size USB A ports.

The hardest part about connecting Lapdock is getting the cables and adapters. Most HDMI and USB cables are designed to plug into jacks, whereas the Lapdock has plugs so the cables/adapters must have Micro HDMI and Micro USB female connections. These are unusual cables and adapters, so check the links.

Lapdock uses the HDMI plug to tell if a phone is plugged in by seeing if the HDMI DDC/CEC ground pin is pulled low. If it"s not, Lapdock is powered off. As soon as you plug in a phone or RasPi, all the grounds short together and Lapdock powers itself on. However, it only does this if the HDMI cable actually connects the DDC/CEC ground line. Many cheap HDMI cables do not include the individual ground lines, and rely on a foil shield connected to the outer shells on both ends. Such a cable will not work with an unmodified Lapdock. There is a detailed "blog entry on the subject at element14: Raspberry Pi Lapdock HDMI cable work-around. The "blog describes a side-benefit of this feature: you can add a small power switch to Lapdock so you can leave RasPi attached all the time without draining the battery.

When you do not connect a HDMI monitor, the GPU in the PI will simply rescale (http://en.wikipedia.org/wiki/Image_scaling) anything that would have appeared on the HDMI screen to a resolution suitable for the TV standard chosen, (PAL or NTSC) and outputs it as a composite video signal.

The Broadcom BCM2835 only provides HDMI output and composite output. RGB and other signals needed by RGB, S-VIDEO or VGA connectors are however not provided, and the R-PI also isn"t designed to power an unpowered converter box.

Note that any conversion hardware that converts HDMI/DVI-D signals to VGA (or DVI-A) signals may come with either an external PSU, or expects power can be drawn from the HDMI port. In the latter case the device may initially appear to work, but there will be a problem, as the HDMI specs only provide in a maximum of 50mA (@ 5 Volt) from the HDMI port, but all of these adapters try to draw much more, up-to 500mA, in case of the R-PI there is a limit of 200mA that can be drawn safely, as 200mA is the limit for the BAT54 diode (D1) on the board. Any HDMI to VGA adapter without external PSU might work for a time, but then burn out D1, therefore Do not use HDMI converters powered by the HDMI port!

Alternatively, it may be possible to design an expansion board that plugs into the LCD headers on the R.Pi. Here is something similar for Beagleboard:

The schematics for apples iPhone 3gs and 4g suggest they speak DSI, thus they can probably be connected directly. The older iPhones use a "Mobile Pixel Link" connection from National Semiconductor. The 3GS panel (480×320) goes as low as US $14.88, while the 4G one (960×640, possibly the LG LH350WS1-SD01, with specifications) can be had for US $17.99 or as low as US $14.28. The connectors used might be an issue, but this connector might fit. Additional circuitry might be necessary to provide the display with required 1.8V and 5.7V for operation, and an even higher voltage for the backlight.

Texy"s 2.8" TFT + Touch Shield Board: HY28A-LCDB display with 320 x 240 resolution @ 10 ~ 20fps, 65536 colors, assembled and tested £24 plus postage, mounts on GPIO pins nicely matching Pi board size, or via ribbon cable

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

In 2015 LG Display announced the implementation of a new technology called M+ which is the addition of white subpixel along with the regular RGB dots in their IPS panel technology.

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

Brody, T. Peter; Asars, J. A.; Dixon, G. D. (November 1973). "A 6 × 6 inch 20 lines-per-inch liquid-crystal display panel". 20 (11): 995–1001. Bibcode:1973ITED...20..995B. doi:10.1109/T-ED.1973.17780. ISSN 0018-9383.

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

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

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

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

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

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

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

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

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

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In fact, the Atomos Ninja V can even improve the quality of footage your camera can shoot! For example, if you have a Panasonic Lumix S5, you can shoot 12-bit RAW instead of 10-bit 4:2:2.

The display isn’t a touchscreen, which is a drawback. But you get a lovely 160-degree viewing angle. This wide-angle view gives you more viewing options. And it makes it easier to get the exact shot you need.

Its screen is only 5.5 inches, and it can’t record video. But it offers excellent connectivity, supporting 3G-SDI, HDMI, HDMI-SDI cross-conversion, and Bluetooth.

It also fits onto a DSLR hot shoe, can cope with 4K video (with loop-through HDMI output), and has two customizable function keys. It offers similar bells and whistles to more expensive on-camera monitors.

The Blackmagic Design HDR monitor is at the top end of the market for on-camera monitors. Plus, it’s the only one that can capture Blackmagic’s RAW code video. (When you shoot with a model from its Pocket Cinema Camera range.)

It has RAW compatibility. It has all the ports you need for professional recording. And it also offers 3D LUTs, professional scopes, exposure tools, and focus-assist features.

It shares the Ninja V’s ability to show HDR pictures a camera’s LCD might not cope with. And there are plenty of display options, such as waveforms and histograms. Everything is easy to find in the user-friendly menu system. And it even supports 1D and 3D LUTs.

The Shinobi is ideal for vlogging cameras and social media creators. It’s a lightweight and portable LCD monitor. And there’s a special mirror mode for selfies and vloggers. The good battery life is another positive. And so is the reasonable price.

It offers real-time recording capabilities in 4K. And you can use formats such as ProRes RAW and CinemaDNG. Also, built-in presets can cope with camera manufacturers’ log video formats.

The Neewer F100 is a basic monitor with a large screen. It’s ideal for beginner Canon cameras. It has various “extras,” including an AV-HDMI cable and a hot shoe ball head. You also get a shoe mount and a sun hood.

HDMI (Type A) input and output, BNC (3G-SDI/HD-SDI) input and output, SDI and HDMI embedded audio, 1/8-inch (3.5 mm) headphone output, barrel (10 VDC) power input, and USB 2.0 (Micro-USB) input

Alternatively, you can link the camera and external monitor with an HDMI cable. And most monitors also allow you to “loop” footage to other monitors or devices. This is handy if you’re working with an assistant on set.

Some of the more high-end on-camera monitors not only increase the size of your display but can improve your camera"s video functionality. For example, when shooting with a Panasonic Lumix S5(opens in new tab) and an Atomos Ninja V external recorder, you can shoot 12-bit RAW instead of 10-bit 4:2:2 with its internal recording option. On-camera monitors are also great additions if your camera lacks features such as a fully articulating screen such as the Blackmagic Pocket Cinema Camera 6K(opens in new tab).

Since the release of the Atomos Ninja V back in 2018, it has become pretty much the industry standard in monitor recorders. It"s a popular choice among both budding and professional videographers and filmmakers thanks to its beautifully calibrated 5-inch HDR display and its ability to support 4K 60p ProRes HQ, H.265, 4:2:2 ad DNxHR. The Ninja V will also support 6K Apple ProRes RAW and it"s the only monitor of this size to do so thanks to a deal between Apple and Atomos. Other features include pro-level monitor tools such as waveforms, false colors, HDR monitoring and LUT support.

The Blackmagic Video Assist 5-inch is the only recorder in our round-up that can capture Blackmagic"s own RAW code video introduced on its Pocket Cinema Camera Range and is an ideal option for any editors who use Davinci Resolve to grade and edit.

Announced at IBC 2019(opens in new tab), it excited video enthusiasts given its potential to tap into the RAW potential of compatible Canon and Panasonic cameras - Blackmagic is in talks with both manufacturers to ensure Video Assist works well with their products.

This is the big brother of the original Shinobi, offering a much larger 7inch display - and billed as the movie directors and focus directors, but also as a great presentation screen for vloggers wanting to see clearly what they are recording. Its bright 2200-nit screen is the key attraction here - but it also does much more than just monitoring your image. With HDR capability - it offers built-in Log conversion, so you can see what your raw footage is likely to look like when edited, and you can even load up your own LUTs via the built-in SD card slot.

Blackmagic Video Assist is a portable monitor, a professional recorder, a portable scope and a fantastic camera viewfinder solution! You can also add better quality record codecs and a larger monitor to any SDI or HDMI camera! The new design has innovations such as 4 built in scopes, enhanced focus assist features, a tally indicator and built in 3D LUTs. The 3G models support formats up to 1080p60 and the 12G HDR models up to 2160p60. The 12G HDR models have a brighter touchscreen for shooting HDR digital film and for outdoor shooting in sunlight. Plus the 12G HDR models support Blackmagic RAW recording from supported cameras! The new design also has L‑Series batteries for longer life. Blackmagic Video Assist really is 4 products in one!

This model supports video formats up to 1080p60 and has a large 5" LCD with focus peaking, zebra and false color. Connections include 3G‑SDI and HDMI. This model includes a single SD Card recorder for ProRes recording. Other features include WFM, vector, histogram and RGB parade scopes plus 3D LUTs!

This model includes all of the 3G model features, but has faster 12G‑SDI and Ultra HD HDMI connections for all formats up to 2160p60. This model includes a bright wide gamut LCD for HDR as well as HDR scopes. Plus a locking power connector. This model also records to an SD card or USB‑C flash disks!

The 7" model has the same great features as the 5" 12G HDR, however supports a larger 7" HDR LCD screen. You also get 2 SD card recorders and recording to external USB‑C flash disks. Both Blackmagic Video Assist 12G models also record Blackmagic RAW from supported cameras.

All Video Assist models are dominated by a large touchscreen with all controls for recording, playback of clips, viewing scopes and setting focus assist features. Both 7" models are large enough to include analog inputs for audio and two SD card slots so you get continuous recording, with automatic recording to the second card. Both of the 12G models include 12G-SDI and Ultra HD HDMI connections and USB-C for recording direct to external flash media disks. All models include a rear tally light, a front panel speaker for clip playback and a headphone jack! Video Assist uses Sony L-Series batteries, and with 2 battery slots, you can change batteries without interrupting recording!

With large and bright 5" and 7" touchscreens, Video Assist makes it incredibly easy to frame shots and accurately focus. The touchscreen displays critical information while you’re shooting including the timecode, transport control, audio meters and a histogram for exposure. You can also customize the LCD to add or remove overlays such as current filename, focus peaking, zebra, false color, frame guides, 3D LUTs and more. 3D LUTs support allows monitoring shots with the desired color and look, plus you can even "bake in" the LUT if you want to record it into the file. If you"re using Blackmagic RAW, the 3D LUT is only added into the metadata so it can be disabled in post production.

Blackmagic Video Assist is an ideal upgrade for cameras, as its bright display is bigger than the tiny displays found on consumer cameras, plus you"re also adding professional focus assist features and better quality file formats. Video Assist is also a great solution for professional cameras because you can use it to upgrade older broadcast cameras to modern file formats used on the latest editing software. You get support for all editing software as you can record in Apple ProRes and Avid DNx. You can even use Blackmagic RAW on supported cameras. With both HDMI and SDI inputs you can connect it to any consumer camera, broadcast camera or even DSLR cameras.

The innovative touchscreen LCD user interface provides incredible control. On screen, there are dedicated buttons for play, stop and record, plus a mini timeline for scrolling through your recordings. You can even image swipe to jog! The LCD includes a heads up display of timecode, video standard, media status as well as audio meters. Scopes can be enabled via the touchscreen as well as focus and exposure assist. There"s also an extensive range of settings all controlled from the large LCD. Plus you can load and save 3D LUTs!

Video Assist features a wide range of video and audio connections such as multi-rate SDI for SD, HD on all models and Ultra HD on the 12G-SDI models. HDMI is included for HDMI cameras and monitoring to consumer televisions and video projectors. The 7" model features Mini XLR inputs which are provided for audio input from microphones and external audio mixers. The USB-C connection lets you plug in external flash disks or SSDs for recording, which means you can get extremely long record durations because flash disks are often much larger than the physically smaller SD Cards. Video Assist even includes a 12V DC power connection and the 12G models include a locking power connector.

Video Assist records using standard open file formats so you don’t have to waste time transcoding media. Files are compatible with all post production software so you can work with the software of your choice, including DaVinci Resolve Studio. Recording works in industry standard 10-bit ProRes or DNx files in all formats and from all HDMI or SDI cameras, as well as 12-bit Blackmagic RAW on the 12G-SDI HDR models when connected to supported cameras. Blackmagic RAW is the fastest growing RAW format and developers can download and use the free Blackmagic RAW SDK to add support to their applications. Best of all media files work on all operating systems!

Blackmagic RAW is a revolutionary format designed to capture the quality of sensor data from cameras. Video Assist supports Blackmagic RAW recording from Leica, Panasonic, Fujifilm, Nikon, Canon and Sigma cameras. Popular camera formats such as H.264 are highly compressed resulting in noise and processing artifacts. Blackmagic RAW eliminates these problems so you get incredible detail and color throughout the production pipeline from camera to edit, color and mastering. It also saves camera settings in metadata so you can set ISO, white balance and exposure, then override them later while editing. Only Blackmagic RAW gives you the highest quality, smallest files and fastest performance!

On the Video Assist 12G models you"ll be ready for the latest HDR workflows as they support the latest HDR standards and include an extremely bright screen with a wide color gamut. Plus the high brightness screen makes shooting outdoors in sunlight easy! The built in scopes even support HDR when required. Files are tagged with the correct HDR information which means SDI and HDMI inputs will also automatically detect HDR video standards. Static metadata PQ and HLG formats are handled according to the ST2084 standard. The bright LCD has a wider color gamut so it can handle both Rec. 2020 and Rec. 709 colorspaces. The Video Assist LCD color gamut can even handle 100% of the DCI‑P3 format.

Some cameras can output logarithmic colorspace to preserve the dynamic range, which is great for later post production, however when these files are viewed on a monitor they can look flat and washed out. 3D LUTs solve this problem because they allow you to apply a "look" to the monitor so you get an idea of how the finished images will look like when editing. LUTs can be applied temporarily for monitoring only, or they can be burned into files for use in editing when capturing Blackmagic RAW. Video Assist works with industry standard 17 and 33 point 3D LUT files, or you can work with the built in LUTs such as Extended Video, Film to Video and more.

You get full support for the most popular video standards. The SDI and HDMI connections are multi-rate, so all models handle SD and HD television standards plus the 12G models add extra support for Ultra HD standards. Standard definition formats include NTSC and PAL. 720p HD standards include 720p50 and 59.94p. 1080i HD interlaced formats include 1080i50 and 59.94. 1080p HD formats include 1080p23.98, 24, 25, 29.97, 30, 50, 59.94 and 60p. Plus you can even work in 1080 PsF formats. On the Blackmagic Video Assist 12G models you also get support for Ultra HD formats up to 2160p59.94. On these 12G models you can even record 2K and 4K DCI rates up to 25p for digital film work!

The HDMI audio/video interface standard is everywhere: TVs, set-top boxes, media streamers, Blu-ray players, A/V receivers, gaming consoles, camcorders, digital cameras, and even a few smartphones. You’ll also find an HDMI output port in most consumer desktop and laptop computers, as well as an input port on many all-in-one PCs, to enable a gaming console or a set-top box may use its internal display.

Given HDMI’s ubiquity, you might have forgotten about the other digital audio/video standard: DisplayPort. Though you’ll find it alongside HDMI on most late-model, high-end video cards, as well as in Macs and laptops marketed to business users, it rarely appears in Windows PCs aimed at consumers. It’s also rare as hen’s teeth in consumer electronics devices.

Both HDMI and DisplayPort can deliver high-definition digital video and high-resolution audio from a source device to a display, so what’s the difference and why might you want DisplayPort when HDMI is so common? And what does a future with burgeoning USB Type-C ports hold? We’ll answer those questions and more; but first, the tale of how the two standards came to be, and which entities control them.

The HDMI (High Definition Multimedia Interface) specification was conceived in 2002 by six consumer electronics giants: Hitachi, Panasonic, Philips, Silicon Image, Sony, and Toshiba. Today, HDMI Licensing, LLC, a wholly owned subsidiary of Silicon Image, controls the spec, but some 80-odd vendors are members of the HDMI Forum. Member or not, manufacturers must pay a royalty for including HDMI in their products. They of course, pass that cost along to you.

The DisplayPort specification was developed by, and remains under the control of VESA (the Video Electronics Standards Association), a large consortium of manufacturers ranging from AMD to ZIPS Corporation—nearly all of which also belong to the HDMI Forum. You’ve likely heard the name VESA in relationship to video before. Most TV manufacturers, for instance, adhere to the organization’s wall-mount standard.

DisplayPort debuted in 2006 as part of an effort to replace two older standards used primarily for computer displays: VGA (Video Graphics Array, an analog interface first introduced in 1987) and DVI (Digital Video Interface, introduced in 1999). DisplayPort is a royalty-free product, but that wasn’t enough to overcome HDMI’s four-year momentum. Computers, with their shorter technology cycles and often greater display needs, were another matter.

HDMI, recently revised to version 2.1, is capable of supporting bit rates up to 48Gbps. VESA even more recently announced DisplayPort 2.0, which can handle raw throughput up to 80Gbps. At the time of this writing, however, DisplayPort 2.0 had not been implemented in any devices; and HDMI 2.1, which makes many of its features optional, has been fully adopted in relatively few real-world products. Current Samsung 8K TVs, for example, use HDMI 2.1’s increased video bandwidth, but they don’t support eARC for audio transport. LG’s new 8K OLED implements both. This scenario is unlikely to change for a while.

HDMI and DisplayPort are similar when it comes to practical applications, and the industry largely views them as complimentary standards. Indeed, HDMI 2.1 offers VESA’s Display Stream Compression. DisplayPort’s raw specs are certainly more impressive, but HDMI’s capabilities have always been more than adequate for the mainstream A/V market.

Note that both standards can drive older display types, both via adapters and adapter cables: HDMI to VGA and DVI; and DisplayPort to VGA, DVI, and HDMI. Both standards are also backward compatible, falling back to the oldest revision used in a connection.

Definitions:bpp is bits per pixel. 24bpp/3 subpixels = 8-bit color; 30bpp/3 = 10-bit color. 4:4:4 means full color and luminance data is being delivered. 60Hz and 60fps are equivalent. HDMI supports a second video stream, which can be used for a second display or for picture-in-picture/picture-by-picture, but it’s rarely implemented. The DisplayPort cable spec allows for power transmission on pin 20, but these days, only Thunderbolt 1 and 2 support power carriage.

HDMI and DisplayPort do the same things, but in very different ways, and there are features unique to each. HDMI explicitly supports CEC (Consumer Electronics Control) for controlling entire A/V setups, and an HDMI cable can carry ethernet information. ethernet requires a purpose-built cable as described in Cables section below. DisplayPort supports CEC over an auxiliary channel, but it’s rarely if ever implemented, due simply to DisplayPort’s faint footprint in the consumer electronics world.

Probably the biggest practical difference between the two standards is that DisplayPort can drive four daisy-chained displays and HDMI can drive just two, with implementations of the latter being extremely scarce.

Note that the 48Gbps per second and the 80Gbps quoted above are the raw HDMI 2.1 and DisplayPort delivery speeds respectively. DisplayPort 2.0 has four lanes that can deliver approximately 77.37Gbps (19.34Gbps per lane) of actual data, while DisplayPort 1.4a can deliver 32.4Gbps (6.48Gbps per lane); HDMI 2.0 delivers 14.4Gbps; and the older HDMI 2.1 offers 42.6Gbps.

Both standards support HDR (High Dynamic Range), with its wider brightness and color gamuts, but HDMI 2.0x only supports static metadata (HDR10), while HDMI 2.1 and DisplayPort 1.4a/2.0 both support dynamic metadata (HDR10+, etc).

HDMI and DisplayPort handle 192Hz/24-bit audio, but with HDMI, that’s only over a single cable connection. That’s fine for high-resolution audio buffs with an HD audio player and an A/V receiver. But to pass audio from a TV tuner or pass it through from a device attached to the TV to an A/V receiver, HDMI 1.4 and 2.0 use ARC (Audio Return Channel), which is limited to two channels of 44.1Hz/16-bit uncompressed audio.

ARC supports highly compressed 5.1 surround, but uncompressed 5.1 and 7.1 audio, as well as sample rates up to 192kHz/24-bit are now possible via HDMI 2.1’s eARC (enhanced ARC) standard.

HDMI connectors have 19 pins and are most commonly seen in three sizes: Type A (standard), Type C (mini), and Type D (micro). Of these, Type A is what you’ll find on TVs, Blu-ray players, soundbars, and other large A/V components; Type C is often found on smaller devices, such as dash cams; and you’ll typically encounter Type A on phones and tablets. A fourth category of HDMI connector, Type E, is used for automotive applications.

Most HDMI connectors rely on friction to stay in place, although some vendors have developed proprietary locking mechanisms designed to prevent the cable from pulling loose.

The three types of HDMI connectors you’re most likely to encounter are (from left to right) standard, mini, and micro. A fourth connector type, for automotive applications, is not shown here.

One thing to know about HDMI cables is that while there is a layout specification (i.e., the number or wires, pin connections, etc.), and the cable type is category 3 (twisted pairs with no shielding required), there isn’t a spec for the materials used in the cable’s construction. Hence, HDMI signals can also be run over CAT5 or CAT6 cable (with a maximum resolution of 1080p), or over fiber-optic cable, according to HDMI Licensing LLC. Active cables with signal-booster circuitry, meanwhile, can be longer and thinner (up to 130 feet, compared to 65 feet for passive cables). Thinner cables are less likely to fail when forced to make hard bends.

There are currently three bandwidth standards and logos you might see, with a variant of each that re-tasks two wires to carry ethernet. That’s including the new Ultra cables from the HDMI 2.1 spec.

Ultra High Speed HDMI Cable: These cables are capable of carrying HDMI 2.1’s full 48Gbps, which is good for 8K, 8K UHD, as well as flavors of 10K if the video is compressed. As three wires have been re-tasked, this might send some lesser cables to the bench. The ethernet cable variant remains at 100Mbps, according to the HDMI Forum’s feature table.

We’ve used any number of HDMI cables, from many eras, without encountering any issues, including passive 25-footers carrying 4K UHD signals. That said, 8K might be different; or it might not. The upshot is that you should try the cables you own with your new devices, and only upgrade them if you run into problems.

The story on DisplayPort cables is a bit simpler in that there’s one basic 5-meter (16 feet) cable design, and only two connectors: full and mini; but as with HDMI, there are types and certification levels, as shown below.

Active copper DisplayPort cables draw power from the DisplayPort connector to operate a signal amplifier embedded in the connector, and they can be considerably longer than passive cables.

When USB 3.1 showed up, a corollary standard for a new, updated connector was also introduced: USB Type-C, or as it’s now officially titled—USB-C. The USB Implementers Forum can call it what it want