Display motion blur

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Display motion blur, also called HDTV blur and LCD motion blur, refers to several visual artifacts (anomalies or unintended effects affecting still or moving images) that are frequently found on modern consumer high-definition television sets and flat panel displays for computers.

Contents

Causes

Many motion blur factors have existed for a long time in film and video (e.g. slow camera shutter speed). The emergence of digital video, and HDTV display technologies, introduced many additional factors that now contribute to motion blur. The following factors are generally the primary or secondary causes of perceived motion blur in video. In many cases, multiple factors can occur at the same time within the entire chain, from the original media or broadcast, all the way to the receiver end.

Motion blur has been a more severe problem for LC displays, due to their sample-and-hold nature. [3] Even in situations when pixel response time is very short, motion blur remains a problem because their pixels remain lit, unlike CRT phosphors that merely flash briefly. Reducing the time an LCD pixel is lit can be accomplished via turning off the backlight for part of a refresh. [4] This reduces motion blur due to eye tracking by decreasing the time the backlight is on. In addition, strobed backlights can also be combined with motion interpolation to reduce eye-tracking-based motion blur. [5] [6] Timing when a pixel is lit can also reduce the effects of a slow pixel response time by turning it off during the transition or overshoot.

Fixes

Strobed backlights

Different manufacturers use many names for their strobed backlight technologies for reducing motion blur on sample-and-hold LCDs. Generic names include black frame insertion and scanning backlight.

Motion interpolation

Some displays use motion interpolation to run at a higher refresh rate, such as 100 Hz or 120 Hz to reduce motion blur. Motion interpolation generates artificial in-between frames that are inserted between the real frames. The advantage is reduced motion blur on sample-and-hold displays such as LCD.

There can be side-effects, including the soap opera effect if interpolation is enabled while watching movies (24 fps material). Motion interpolation also adds input lag, which makes it undesirable for interactive activity such as computers and video games. [18]

Recently, 240 Hz interpolation have become available, along with displays that claim an equivalence to 480 Hz or 960 Hz. Some manufacturers use a different terminology such as Samsung's "Clear Motion Rate 960" [9] instead of "Hz". This avoids incorrect usage of the "Hz" terminology, due to multiple motion blur reduction technologies in use, including both motion interpolation and strobed backlights.

Manufacturer Terminology:

Laser TV

Laser TV has the potential to eliminate double imaging and motion artifacts by utilizing a scanning architecture similar to the way that a CRT works. [25] Laser TV is generally not yet available from many manufacturers. Claims have been made on television broadcasts such as KRON 4 News' Coverage of Laser TV from October 2006, [26] but no consumer-grade laser television sets have made any significant improvements in reducing any form of motion artifacts since that time. One recent development in laser display technology has been the phosphor-excited laser, as demonstrated by Prysm's newest displays. These displays currently scan at 240 Hz, but are currently limited to a 60 Hz input. This has the effect of presenting four distinct images when eye tracking a fast-moving object seen from a 60 Hz input source. [27]

There has also been Microvision's Laser MEMS Based Pico Projector Pro, which has no display lag, no input lag and no persistence or motion blur. [28]

LED and OLED

Both OLED and Sony's Crystal LED displays use an independent light source for every pixel, without a traditional CCFL or LED backlight used in LCD. Sony's Crystal LED [29] uses individual light emitting diodes for each pixel, instead of using LED as a backlight. Several displays demonstrated at the CES 2012 have been the first modern high-definition television sets to overcome the motion artifacts by selectively blanking parts of the screen. [30] Both OLED and "Crystal LED" technologies also have response times far shorter than LCD technology, and can reduce motion blur significantly. However, all consumer OLED displays are sample-and-hold, [2] [31] which leads to the same amount of motion blur as a conventional LCD.

See also

Related Research Articles

<span class="mw-page-title-main">Computer monitor</span> Computer output device

A computer monitor is an output device that displays information in pictorial or textual form. A discrete monitor comprises a visual display, support electronics, power supply, housing, electrical connectors, and external user controls.

<span class="mw-page-title-main">Liquid-crystal display</span> Display that uses the light-modulating properties of liquid crystals

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 directly but instead use a backlight or reflector to produce images in color or monochrome.

<span class="mw-page-title-main">Plasma display</span> Type of flat panel display

A plasma display panel (PDP) is a type of flat panel display that uses small cells containing plasma: ionized gas that responds to electric fields. Plasma televisions were the first large flat panel displays to be released to the public.

<span class="mw-page-title-main">OLED</span> Diode that emits light from an organic compound

An organic light-emitting diode (OLED), also known as organic electroluminescentdiode, is a type of light-emitting diode (LED) in which the emissive electroluminescent layer is an organic compound film that emits light in response to an electric current. This organic layer is situated between two electrodes; typically, at least one of these electrodes is transparent. OLEDs are used to create digital displays in devices such as television screens, computer monitors, and portable systems such as smartphones and handheld game consoles. A major area of research is the development of white OLED devices for use in solid-state lighting applications.

<span class="mw-page-title-main">Flat-panel display</span> Electronic display technology

A flat-panel display (FPD) is an electronic display used to display visual content such as text or images. It is present in consumer, medical, transportation, and industrial equipment.

The refresh rate, also known as vertical refresh rate or vertical scan rate in reference to terminology originating with the cathode-ray tubes (CRTs), is the number of times per second that a raster-based display device displays a new image. This is independent from frame rate, which describes how many images are stored or generated every second by the device driving the display. On CRT displays, higher refresh rates produce less flickering, thereby reducing eye strain. In other technologies such as liquid-crystal displays, the refresh rate affects only how often the image can potentially be updated.

<span class="mw-page-title-main">Display resolution</span> Number of distinct pixels in each dimension that can be displayed

The display resolution or display modes of a digital television, computer monitor or display device is the number of distinct pixels in each dimension that can be displayed. It can be an ambiguous term especially as the displayed resolution is controlled by different factors in cathode ray tube (CRT) displays, flat-panel displays and projection displays using fixed picture-element (pixel) arrays.

<span class="mw-page-title-main">LCD television</span> Television set with liquid-crystal display

A liquid-crystal-display television is a television set that uses a liquid-crystal display to produce images. It is by far the most widely produced and sold type of television display. LCD TVs are thin and light, but have some disadvantages compared to other display types such as high power consumption, poorer contrast ratio, and inferior color gamut.

A thin-film-transistor liquid-crystal display is a type of liquid-crystal display that uses thin-film-transistor technology to improve image qualities such as addressability and contrast. A TFT LCD is an active matrix LCD, in contrast to passive matrix LCDs or simple, direct-driven LCDs with a few segments.

This is a comparison of various properties of different display technologies.

<span class="mw-page-title-main">Active shutter 3D system</span> Method of displaying stereoscopic 3D images

An active shutter 3D system is a technique of displaying stereoscopic 3D images. It works by only presenting the image intended for the left eye while blocking the right eye's view, then presenting the right-eye image while blocking the left eye, and repeating this so rapidly that the interruptions do not interfere with the perceived fusion of the two images into a single 3D image.

Flicker-free is a term given to video displays, primarily cathode ray tubes, operating at a high refresh rate to reduce or eliminate the perception of screen flicker. For televisions, this involves operating at a 100 Hz or 120 Hz hertz field rate to eliminate flicker, compared to standard televisions that operate at 50 Hz or 60 Hz (NTSC), most simply done by displaying each field twice, rather than once. For computer displays, this is usually a refresh rate of 70–90 Hz, sometimes 100 Hz or higher. This should not be confused with motion interpolation, though they may be combined – see implementation, below.

<span class="mw-page-title-main">Motion interpolation</span> Form of video processing

Motion interpolation or motion-compensated frame interpolation (MCFI) is a form of video processing in which intermediate film, video or animation frames are generated between existing ones by means of interpolation, in an attempt to make animation more fluid, to compensate for display motion blur, and for fake slow motion effects.

Display lag is a phenomenon associated with most types of liquid crystal displays (LCDs) like smartphones and computers and nearly all types of high-definition televisions (HDTVs). It refers to latency, or lag between when the signal is sent to the display and when the display starts to show that signal. This lag time has been measured as high as 68 ms, or the equivalent of 3-4 frames on a 60 Hz display. Display lag is not to be confused with pixel response time, which is the amount of time it takes for a pixel to change from one brightness value to another. Currently the majority of manufacturers quote the pixel response time, but neglect to report display lag.

<span class="mw-page-title-main">Quantum dot display</span> Type of display device

A quantum dot display is a display device that uses quantum dots (QD), semiconductor nanocrystals which can produce pure monochromatic red, green, and blue light. Photo-emissive quantum dot particles are used in LCD backlights or display color filters. Quantum dots are excited by the blue light from the display panel to emit pure basic colors, which reduces light losses and color crosstalk in color filters, improving display brightness and color gamut. Light travels through QD layer film and traditional RGB filters made from color pigments, or through QD filters with red/green QD color converters and blue passthrough. Although the QD color filter technology is primarily used in LED-backlit LCDs, it is applicable to other display technologies which use color filters, such as blue/UV active-matrix organic light-emitting diode (AMOLED) or QNED/MicroLED display panels. LED-backlit LCDs are the main application of photo-emissive quantum dots, though blue OLED panels with QD color filters are being researched.

PenTile matrix is a family of patented subpixel matrix schemes used in electronic device displays. PenTile is a trademark of Samsung. PenTile matrices are used in AMOLED and LCD displays.

<span class="mw-page-title-main">Graphics display resolution</span> Width and height of an electronic visual display device, such as a computer monitor, in pixels

The graphics display resolution is the width and height dimension of an electronic visual display device, measured in pixels. This information is used for electronic devices such as a computer monitor. Certain combinations of width and height are standardized and typically given a name and an initialism which is descriptive of its dimensions. A graphics display resolution can be used in tandem with the size of the graphics display to calculate pixel density. An increase in the pixel density often correlates with a decrease in the size of individual pixels on a display.

Universal Display Corporation is a developer and manufacturer of organic light emitting diodes (OLED) technologies and materials as well as provider of services to the display and lighting industries. It is also an OLED research company. Founded in 1994, the company currently owns or has exclusive, co-exclusive or sole license rights with respect to more than 3,000 issued and pending patents worldwide for the commercialization of phosphorescent based OLEDs and also flexible, transparent and stacked OLEDs - for both display and lighting applications. Its phosphorescent OLED technologies and materials are licensed and supplied to companies such as Samsung, LG, AU Optronics CMEL, Pioneer, Panasonic Idemitsu OLED lighting and Konica Minolta.

A see-through display or transparent display is an electronic display that allows the user to see what is shown on the screen while still being able to see through it. The main applications of this type of display are in head-up displays, augmented reality systems, digital signage, and general large-scale spatial light modulation. They should be distinguished from image-combination systems which achieve visually similar effects by optically combining multiple images in the field of view. Transparent displays embed the active matrix of the display in the field of view, which generally allows them to be more compact than combination-based systems.

References

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