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.
TN displays have a twist (the rotation of the molecules from one plane of the display to the other) of 90 degrees or less.
HTN (High Twisted Nematic) displays are based on a higher molecular twist (usually 110°) than TN (90°) and therefore offer wider viewing angles and improved contrast. In fact, these HTN products offer viewing characteristics close to those of STN technology. As low operating voltage as 2.5V and marginal extra cost over TN means that the products are well suited to hand-held applications.
Super Twisted Nematic LCD´s have a twist that is greater than 90 but less than 360 degrees. Currently most STN displays are made with a twist between 180 and 270 degrees. The higher twist angles cause steeper threshold curves which put the on and off voltages closer together. The steeper thresholds allow multiplex rates greater than 32 to be achieved.
This adds a retardation film to the STN display that compensates for the color added by the birefringence effect. This allows a black and white display to be produced and provides for a higher contrast and wider viewing angle.
DSTN was the first commercial black and white conversion of the STN display. DSTN displays are actually two distinct STN filled glass cells glued together. The first is a LCD display, the second is a glass cell without electrodes or polarizer’s filled with LC material for use as a compensator which increases contrast and gives the black on white appearance.
Color STN Technology is actually STN technology that uses a white backlight and color filters to produce the hues required for a color display. Each visual pixel of a CSTN display is actually physically 3 separate pixels using a colored filter of Red. Green and Blue. Each of those colors are controlled individually by the graphic controller chip. So in actually; a 320 by 240 pixel CSTN display actually contains 960 by 240 individually colored pixels.
A positive image on an LCD display is when the pixel is "OFF" it is transparent, when a pixel in "ON" it is opaque.
A negative image on an LCD display is when the pixel is "OFF" it is opaque, when a pixel in "ON" it is transparent.
A Transmissive LCD polarizer, unlike the reflective polarizer, allows all the light from the backlight to pass thought the bottom and top layer of glass towards the user. The backlight must be on for the display to be readable.
The Transflective LCD polarizer is a combination, or hybrid, of the Reflective and the Transmissive polarizer. It reflects some of the ambient light passing through the front of the glass and at the same time allows some of the light from the backlight to pass through to the front layer of glass.
The reflective LCD polarizer is nothing more than a mirror that is applied to the bottom layer of glass. It reflects 100% of the ambient light entering through the top layer of glass back towards the user.
The marked size of liquid crystal display is the actual use scope of the screen.
The visual angle of liquid crystal display is horizontal symmetrical, but it is not always vertically symmetrical.
The definition of contrast ratio is that the maximum luminance value (all white) divides by the minimum luminance value (all black).
The definition of response time is that the reaction time of liquid crystal for the input signal.
This is a measurement of the amount of light the LCD monitor produces.
It is a measurement that defines the sharpness of a display. Pixel pitch describes the density of the pixels (LED clusters) on an LED display and correlates with resolution. Sometimes referred to as pitch or dot pitch, the pixel pitch is the distance in millimeters from the center of a pixel to the center of the adjacent pixel. Since pixel pitch indicates the amount of space between two pixels, a smaller pixel pitch means there is less empty space between pixels. This equates to higher pixel density and improved screen resolution.
The basic color of LCD which usually has 64 degree, so each single pixel has 64*64*64=262144 kinds of colors. Only some excellent manufacturers are using the so-called FRC(Frame Rate Control) technology which is exhibiting full color images with a simulation way. And each basic color has 256*256*256=16777216 kinds of colors.
A Light Guide Plate is an acrylic panel typically made from pure PMMA resin. It is a transparent acrylic panel made from pure PMMA virgin sheet. It distributes the light coming from the light source evenly over the whole upper face to acrylic panel. It is a key component to maximize the uniformity of light, to make backlight slim and to reorient the lines or dot light source such as decoration lamp or LED to the plate.
A polarizer or polariser is an optical filter that lets light waves of a specific polarization pass through while blocking light waves of other polarizations.
This assembly requires that the liquid-crystal molecules at the two glass surfaces of the cell can be arranged in parallel to the two polarizer foils. This is achieved by coating the surfaces of the cell with a thin, transparent film of polyimide, comprising long chain-like molecules. When this film is rubbed by a velvet cloth, microscopic groves are generated in the polyimide layer and the molecule chains line up in the rubbing direction. This guides the liquid crystals at the surface into the same orientation. The result is a twisted or helical structure of the liquid crystal molecules which try to align parallel to each other.
An electrophotographic printer that uses a single light source directed by liquid crystal shutters.
Screen printing is a technology, where the print material is pressed by a squeegee through a mesh that is fixed on a frame. The mesh carries a photoresist layer with openings defining the pattern to be printed.
The function of the screen frame is to providing a means for mounting the mesh, withstanding the force of the tensioned mesh, standing up to additional forces applied during printing, remaining flat and square and being light enough to handle easily.
It will allow the printing material to pass through the screen easily.
Forcing the print material into the mesh - influenced by mesh opening size and viscosity.
Flexographic Printing is a printing method in which liquid printing ink is placed on a printing plate made of rubber, resin or other soft material and then transferred to a substrate.
BEF which is abbreviated for Brightness Enhancement Film and also is called Prism Sheet is the key components of backlight module and accounts for the highest proportion of the cost in the backlight module.
The main function of normal prism sheet is going to guide the light angle and increase the luminous efficiency.
It is also called DBEF (Dual Brightness Enhancement Film) which is a unique patented product of 3M. It reuses the light of the backlight unit by utilizing the recycling light mechanism which makes the light pass through more than 800 different refractive index optical material layers and fully reflect.
Micro-lens film combines diffuser and prism functions in one film by using a micro-lens array structure. Many LCD TV panel makers replace conventional prism sheets with micro-lens films.
For small cells, the filling of displays with liquid crystals is done by sucking the liquid crystals into the cell after evacuation of the cell. For large LCDs this method is too slow and a new technology for integrated filling of LCDs in a vacuum assembly machine has been developed. This technology is called one drop filling ODF-Technology, because the exact volume of liquid crystals which is necessary to fill the cell is dispensed on the lower glass plate before cell assembly is done. This method requires extremely precise dispensing technology because too much liquid would cause an overflow of the cell during assembly and pressing, while too less liquid would create bubbles in the LCD. Vacuum assembly is necessary in order to avoid gas bubble enclosure.
The ITO glass is a thin transparent film similar to common glass, but unlike glass, it is a conductor of electricity because it is a kind of transparent conductive oxide (TCO).
IPS is a screen technology for liquid-crystal displays. It was designed to solve the main limitations of the twisted nematic field effect matrix LCDs .
The diffusion film is the spread material that transforms the linear light source of CCFL or the point light source of LED into a uniform surface light source in the LCD module.
It is flexible and no welding, rapid assembly and disassembly, it has a better shock resistance.
Metal pin connection can be soldered directly to the printed circuit board.
A printed circuit board and a LCD are connected by flexible zebra paper, which adopts the heat sealing processing or the soldering processing and can be use in all kind of harsh environments.
The color temperature is that human eyes see the variation of the color when light waves are in different energy.
An organic light-emitting diode (OLED) is a light-emitting diode (LED) in which the emissive electroluminescent layer is a film of organic compound that emits light in response to an electric current.
An electronic paper display (EPD) is an electrically-charged surface that replicates the look and experience of ink on paper.
Backlight is a category of illumination used in monitors utilizing liquid crystal display (LCD) technology.
Backlighting is the process of illuminating the subject from the back.
A reflector is an improvised or specialised reflective surface used to redirect light towards a given subject or scene.
A light-emitting diode (LED) is a semiconductor light source that emits light when current flows through it.
Electroluminescence (EL) is an optical phenomenon and electrical phenomenon in which a material emits light in response to the passage of an electric current or to a strong electric field.
Backlight dimming is a dominant method for power reduction in LCDs.
A diffuser is a semi translucent material placed between a light source and a subject which scatters light beams to soften light.
An organic light-emitting diode (OLED) is a light-emitting diode (LED) in which the emissive electroluminescent layer is a film of organic compound that emits light in response to an electric current.
Transparent OLEDs use transparent or semi-transparent contacts on both sides of the device to create displays that can be made to be both top and bottom emitting (transparent). TOLEDs can greatly improve contrast, making it much easier to view displays in bright sunlight. This technology can be used in Head-up displays, smart windows or augmented reality applications.
Graded heterojunction OLEDs gradually decrease the ratio of electron holes to electron transporting chemicals. This results in almost double the quantum efficiency of existing OLEDs.
Stacked OLEDs use a pixel architecture that stacks the red, green, and blue sub pixels on top of one another instead of next to one another, leading to substantial increase in gamut and color depth, and greatly reducing pixel gap. Currently, other display technologies have the RGB (and RGBW) pixels mapped next to each other decreasing potential resolution.
In contrast to a conventional OLED, in which the anode is placed on the substrate, an Inverted OLED uses a bottom cathode that can be connected to the drain end of an n-channel TFT especially for the low cost amorphous silicon TFT backplane useful in the manufacturing of AMOLED displays.
A passive-matrix display is an LCD screen display that contains a series of wires that cross each other. See the dual scan display for a full definition on this term.
A thin-film transistor (TFT) is a type of field-effect transistor that is usually used in a liquid crystal display (LCD).
PWM is a method used for dimming a monitors backlight whereby the backlight is turned off and on rapidly to simulate lower brightness levels.
Dithering and Frame Rate Control (FRC) relate to the colour depth of a monitor panel and are technologies used to boost the colours which the matrix can display.
This dithering method involves assigning appropriate colour values from the available colour palette to close-by pixels in such a way that it gives the impression of a new colour tone which otherwise could not have been created at all.
The other method is Frame-Rate-Control (FRC), also referred to sometimes as temporal dithering. This works by combining four colour frames as a sequence in time, resulting in perceived mixture.
It is the creation of new values that lie between known values.
Aspect ratio is an image projection attribute that describes the proportional relationship between the width of an image and its height.
Backlight leakage refers to the problem some screens exhibit where in a darkly lit room, and with a dark image on the screen, you can clearly see areas particularly around the edges where the backlight shines through.
On modern IPS panels when viewing a black image there is typically a characteristic white glow when viewed from an angle, commonly referred to as "IPS-glow".
Banding is an issue which you can sometimes spot on a monitor, and involves blocking and gradation of colours to a considerable level.
The Screen Door effect is so called because sometimes it is possible to clearly see the individual pixels in a panel and the gaps between them. This is quite rare, but can be distracting if you are using a TFT up close. It may be more apparent where pixel pitch is large.
Input lag is described as the lag between the output from a graphics card and the image which is displayed on the screen you are using.
It is the LCD and plasma display equivalent of screen burn. Unlike screen burn, the effects are usually temporary and often times not visible without close inspection.
A dead pixel is a picture element in which all three RGB (red, green, blue) sub-pixels are permanently turned off, which creates a black spot in the display. Malfunctioning transistors and manufacturing flaws can result in dead pixels.
Colour reproduction is related to the ability of a panel to produce the colours desired.
A technology used in the flat panel liquid crystal displays of notebook and laptop computers. Active matrix displays provide a more responsive image at a wider range of viewing angle than dual scan (passive matrix) displays. Also known as thin film transistor display .
The number of binary digit (bits) you have in which to describe something.
Brightness is a relative expression of the intensity of the energy output of a Light.
Area for active pixels or icons or segments or pattern.
Area with no imperfection. The background should be same in this area.