|
ACTIVE AREA/EFFECTIVE AREA
In the viewing area of the LCD glass the dimensions of the perimeter of the conductive area.
ANNEALED GLASS
Is glass without internal stresses caused by heat treatment (i.e. by rapid cooling, or by toughening or heat strengthening). Glass becomes annealed if it is heated above a transition point then allowed to cool slowly, without being quenched. Annealed glass breaks into large, jagged shards that can cause serious injury, and thus annealed glass is considered a hazard in architectural applications. Building codes in many parts of the world restrict the use of annealed glass in areas where there is a high risk of breakage and injury, for example in bathrooms, in door panels, fire exits and at low heights in schools or domestic houses.
BEZEL
A frame of plastic or metal fitting over the LCD glass
CELL GAP
The space containing liquid crystal fluid between the two pieces of glass.
CHEMICALLY STRENGTHENED GLASS
Is a type of glass that has increased strength. When broken it still shatters in long pointed splinters similar to float (annealed) glass. For this reason, it is not considered a safety glass and must be laminated if a safety glass is required. Chemically strengthened glass is typically six to eight times the strength of annealed glass. Chemical strengthening results in a strengthening similar to toughened glass, however the process does not use extreme variations of temperature and therefore chemically strengthened glass has little or no bow or warp, optical distortion or strain pattern.
CHIP-ON-BOARD (COB)
The LCD driver chip is mounted directly on the PCB with wires used to connect it to other circuits.
CHIP-ON-GLASS
A technology that mounts the LCD driver chip to the contact edge of the LCD glass.
CHIP-ON-FLEX
The LCD driver chip is mounted to a flexible connector.
CLARITY (Narrow Angle Scattering, See-through quality)
Light is diffused in a small angle range (less than 2.5 degrees) with high concentration.
CONTRAST RATIO
The difference in luminance between the unselected area and the selected area.
DIRECT/STATIC DRIVE
The method in which each conductive lead on the contact edge connects to one segment or enunciator.
DOT/PIXEL
An active element that forms a character or symbol.
DOT MATRIX
A group of dots/pixels forming a character or symbol. Typical 5 across by 7 down.
DSTN (Double STN)
Double STN is a technology, which uses two cells bonded together. One cell is active to produce the image desired. The other cell, called the compensation cell) is not driven but is used in place of a retardation film (see FSTN). Since these cells have equivalent but opposite characteristics over temp, this is a good, wide temperature range display. The main drawbacks are cost, thickness and weight of the 4 pieces of glass.
ELASTOMER CONNECTOR
A silicone rubber strip made up of conductive and non-conductive material.
ESTN (Enhanced STN)
Enhanced STN uses a dark dye added to the basic STN cell. This decreases the background bleed through for short wavelength light. This is often used for negative mode applications but the dye makes response time quite slow at low temps.
FSTN (Film Compensated STN)
Film compensated STN has a “retardation” film added to compensate the base colors of STN, providing an appearance similar to TN LCDs. This is available in both negative and positive mode displays. These materials do not track over wide temp ranges. The result is typically poorer contrast at temperature extremes.
FFSTN (Film Film Compensated STN)
FFSTN uses two of compensation films. This improves light absorption in negative image displays (better contrast), but still suffers from the inability of compensation films to track the LCD’s EO characteristics over temperature.
HAZE
ASTM D 1004 defines haze as the percent of transmitted light that is scattered more than 2.5° from the direction of the incident beam.
Materials with haze values greater than 30% are considered diffusing.
HEAT SEAL
A flexible adhesive connector bonded by heat to the contact edge of the glass.
HEAT-STRENGTHENED GLASS
Is glass that has been heat treated to induce surface compression, but not to the extent of causing it to "dice" on breaking in the manner of tempered glass. On breaking, heat-strengthened glass breaks into sharp pieces that are typically somewhat smaller than those found on breaking annealed glass, and is intermediate in strength between annealed and toughened glasses.
INVERTER, DC to AC
Converts DC to AC at a high frequency, used with electroluminescent lamps (EL).
ISTN (Intelligent STN)
Intelligent STN technology is useful for negative image displays, especially with shorter wavelength backlights. It is an STN cell, with a thin polymer-encapsulated LC compensation film. This is similar to DSTN, but with only one LCD cell (two pieces of glass). It offers similar weight and thickness of a normal STN. Since this film is liquid crystal based, it offers similar compensation over temp as DSTN, and therefore is a good, wide temp range display option. (Sometimes referred to as ASTN.)
LIQUID CRYSTAL FLUID
Consists of bipolar molecules which can twist polarized light when in the OFF state.
MODULE
LCD glass connected to a PCB with drivers on board.
MULTIPLEX
Using multiple backplanes in order to reduce the number of connections between the LCD and the drivers.
Negative Blue Mode STN
“Blue Mode” is the negative image version of STN, with no additional films. This is a very attractive display, which works especially well with white backlights. It is often used in general instrumentation, medical, etc. EO over temp is still an issue.
NEMA Rating
What does NEMA rated mean?
In non-hazardous locations, there are several different NEMA ratings for specific enclosure "types", their applications, and the environmental conditions they are designed to protect against, when completely and properly installed. The following provides an overview of the NEMA Types. For complete definitions, descriptions, and test criteria, see the National Electrical Manufacturers Association (NEMA) Standards Publication No. 250.
NEMA 1
Enclosures constructed for indoor use to provide a degree of protection to personnel against incidental contact with the enclosed equipment and to provide a degree of protection against falling dirt.
NEMA 2
Same as NEMA 1 including protection against dripping and light splashing of liquids.
NEMA 3
Enclosures constructed for either indoor or outdoor use to provide a degree of protection to personnel against incidental contact with the enclosed equipment; to provide a degree of protection against falling dirt, rain, sleet, snow, and windblown dust; and that will be undamaged by the external formation of ice on the enclosure.
NEMA 3R
Same as NEMA 3 excluding protection against windblown dust.
NEMA 3S
Enclosures constructed for either indoor or outdoor use to provide a degree of protection to personnel against incidental contact with the enclosed equipment; to provide a degree of protection against falling dirt, rain, sleet, snow, and windblown dust; and in which the external mechanism (s) remain operable when ice laden.
NEMA 4
Enclosures constructed for either indoor or outdoor use to provide a degree of protection to personnel against incidental contact with the enclosed equipment; to provide a degree of protection against falling dirt, rain, sleet, snow, windblown dust, splashing water, and hose-directed water; and that will be undamaged by the external formation of ice on the enclosure.
OLED
OLED (organic light-emitting diodes) based on the use of organic polymer material as the semiconductor material in light-emitting diodes (LEDs).
PCT (Projected Capacitive Touch)
The PCT technology offers capacitive sensing through a glass lens typically providing gloved or ungloved capability. Depending on the technology employed, the cover lens can range from thicknesses of 3mm to 21mm providing either handheld glass surface or vandal resistant shields.
PITCH
The center dimension of adjacent conductive traces, dots, or connector holes.
PIXEL
The same as "dot"
RCF FILM
REFLECTIVE
A smooth reflective layer bonded to the rear polarizer that reflects incoming ambient light.
SEGMENT
An active element of a digit, usually 7 segments for numeric and 14 segments for alpha/numeric digits.
STATIC DRIVE
Same as "direct drive."
STN (Super Twist Nematic)
Super Twisted Nematic is the main technology used for passive matrix displays. Electro Optical (EO) characteristics change over temperature, but contrast and readability are quite good over a fairly wide range.
TFT
Thin-Film Transistor technology is a liquid crystal display that has a transistor for each pixel.
THRESHOLD VOLTAGE
TOUGHENED GLASS (also known as tempered glass)
Is a type of safety glass that has increased strength and will usually shatter in small, square pieces when broken. Toughened glass would be a problem when a small stone hits the windshield at speed, as it would shatter into the small squares. Toughened glass is typically four to six times the strength of annealed glass. Most toughened glass is made from float glass that has been specially heat-treated.
TRANSFLECTIVE
A reflective layer bonded to the rear polarizer that can reflect some ambient light and also lets the backlight pass through.
TRANSMISSIVE
An LCD which does not have a reflector or transflector.
TRANSMITTANCE
The percent of incident light that is able to pass through a material. The higher the transmittance value, the more transparent a material is.
TWISTED NEMATIC (TN)
A type of liquid crystal where the alignment surface, and therefore the liquid crystal molecules, is oriented 90 degrees from each surface of glass.
VIEWING ANGLE
A cone perpendicular to the LCD in which minimum contrast can be seen.
VIEWING AREA
The dimensions measured from the inside perimeter of the LCD bezel or LCD glass epoxy seal.
ZEBRA(R) CONNECTOR a trademark of Fujipoly America Corp for a brand of elastomer connector.
|