-C-
Term (Acronym) [units]: Definition
Candela [cd/m2]: An international unit of luminous intensity (brightness) per unit of projected area perpendicular to the line of observation. The units of candelas per square meter are also called "nits".
Capacitive Touch: A touch screen technology that uses a uniform electric field across a transparent conductive layer. When a user’s finger touches the layer, the measured amount of current drawn from each corner is used to calculate the location of the touch. Capacitive touch is available in two forms, surface capacitive and projected capacitive.
Capital Expenditures (CAPEX): The total amount of capital-budget money spent by a company to acquire or upgrade physical assets such as manufacturing equipment and factory buildings. The sum of the CAPEX for all display manufacturers is often used as a measure of the market size for capital equipment.
Cathode Ray Tube (CRT): A vacuum tube in which a rapidly-moving electron gun passes across the screen, creating an electron beam that lights selected phosphor dots as it moves. The dots are arranged in groups of three, forming pixels which can be lighted as red, green or blue. By moving across rows of pixels rapidly from top to bottom, the electron beam creates a continuously changing, lighted screen that the human eye resolves into an image. CRTs have been used in televisions and computer monitors for many years; now they are being replaced in all applications by flat panel displays.
Cell: The fabricated glass portion of an LCD, exclusive of the driver circuits, backlight, frame and any other components that make up a complete LCD module. It’s common for one company or manufacturing operation to build the cell and another to assemble the cell into an LCD module.
Cell Gap: The space between the back and front substrates in an LCD. This space contains the liquid crystal material.
Cell Process: The process of joining the back substrate containing the TFTs and the front substrate containing the color filters, then filling the space between the substrates with liquid crystal material. This is the second major process group in manufacturing an LCD.
Character Display: A display that is used to display only letters, numbers and symbols. Character displays are typically characterized by the number of lines they contain times the number of characters per line.
Chemical Vapor Deposition (CVD): A chemical process often used in the semiconductor and display industries for the deposition of thin films of various materials. There are many different kinds of CVD; one of the most commonly used in the display industry is plasma-enhanced CVD (PECVD).
Chip on Board (COB): A bare LCD driver chip (a silicon die with attached wire bonds) is mounted directly on a printed circuit board and encapsulated.
Chip on Flex (COF): An LCD driver chip is mounted on a flexible circuit which is attached to the contact edge of the LCD glass. The flexible circuit is sometimes made of Kapton® film, a DuPont polyimide (PI) film.
Chip on Glass (COG): An LCD driver chip is mounted directly on the surface of the display glass, resulting in a thinner and lighter LCD.
Chip on Stick (COS): An LCD driver chip is mounted directly on a small "stick" of glass which is connected to the LCD via a flexible cable.
Chip on Tab (COT): Another term for Tape Automated Bonding (TAB).
Chromaticity: The part of color specification that does not involve luminance. Chromaticity is two-dimensional and is specified by pairs of numbers indicating wavelength and purity.
Chromaticity Diagram: A two-dimensional graph covering the chromaticity coordinates of visible light (380 nm – 770 nm). The most commonly used chromaticity diagram in the display industry is the CIE 1931 diagram (also called a "color space")
CIE 1931 Color Space: A mathematically defined color space created by the International Commission on Illumintation (CIE) in 1931 based on direct measurements of the human eye in which the three human color dimensions (RGB) are mapped into a two-dimensional graph. This graph is very commonly used to illustrate the color gamut of a flat-panel display.
Co-firing: The combustion (baking) of two different materials at the same time.
Cold Cathode Fluorescent Lamp (CCFL): The standard lamp used in an LCD backlight. These lamps are very thin, typically 2mm in diameter. They are called "cold cathode" because they don’t employ a cathode heater such as those used in a vacuum tube or CRT.
Cold Cathode Fluorescent Tube (CCFT): Same as cold cathode fluorescent lamp (CCFL).
Color Calibration: The adjustment of colors in an output device such as a display to match colors on a standard reference device or on another output device such as a printer.
Color Depth: The number of bits used to produce color in each pixel. The more bits that are used, the greater is the number of colors that can be displayed, provided that the graphics hardware (graphics card and monitor) are capable of displaying them. Common color depth settings are 8 bits (256 colors), 16 bits (65 thousand colors), 24 bits (16 million colors) and 32 bits (4 billion colors).
Color Filter (CF): A pattern of red, green and blue areas on the underneath of the upper glass substrate of an LCD. The color filter creates the LCD’s RGB colors from the normally white backlight. The traditional method of creating color filters requires many wet photolithography steps; DuPont Thermal Color Filter technology replaces this with a lower-cost, laser-based, dry method.
Color Gamut: The subset of colors which can be accurately represented in a given circumstance by a given output device such as a display or printer. The color gamut for a specific display is typically shown as a triangular area within the fingertip-shaped International Commission on Illumination (CIE) 1931 chromaticity diagram.
Color Matching: The process of accurately duplicating colors between a display and either an input device (graphics card) or an output device (printer). Some LCD monitors are capable of storing color-matching data and using it to produce benefits such as WYSIWYG (what you see is what you get) printing.
Color Supertwist Nematic (CSTN): See Supertwist Nematic.
Color Temperature [°K]: A measurement of the color of light radiated by an object while it is being heated. The measurement is expressed in degrees Kelvin; most monitor displays are calibrated to produce a neutral white of 6,500 degrees K. Some other color temperatures include: incandescent lamp, 2,800°K; cool-white fluorescent lamp, 4,200°K; bright midday sun, 5,200°K; hazy sky, 8,000°K; deep blue clear sky, 20,000°K.
Column: A vertical line of pixels.
Column Driver: An electronic circuit (chip) that provides voltages to individual subpixels in a column. These are typically 8-bit driver circuits that provide 256 values (shades) per subpixel.
Commission Internationale de l’Eclairage (CIE): The International Commission on Illumination, the primary international organization concerned with color and color measurement.
Complementary Metal-Oxide Semiconductor (CMOS): A type of integrated circuit that utilizes both p-channel and n-channel MOSFET transistors. CMOS chips include microprocessors, static RAM (SRAM) and other digital logic circuits.
Compound Annual Growth Rate (CAGR): The year-over-year growth rate of an investment compounded over some specified period of time. Commonly used to show average growth rates over a range of years.
Compression: The process of making the storage requirement of data (such as an image or movie) smaller by encoding information using fewer bits. Poor-quality images on HDTV displays are often the result of excessively "lossy" compression. MPEG-2 is the current compression standard that is used to make a movie 15 to 30 times smaller. MPEG-4 is the next generation.
Continuous Grain Silicon (CGS): The name that Sharp has given to its unique crystallization process that combines SPC and ELA.
Contrast: Contrast is the difference in light intensity between the brightest white pixel and the darkest black pixel that a display can produce.
Contrast Ratio: The ratio of the luminosity of the brightest white pixel and darkest black pixel that a display can produce.
Cost of Ownership (COO): The total cost of owning an asset over its lifetime. This is an important metric for capital equipment, which includes initial price, consumable costs, maintenance, utilization, etc.
CPT: Can refer to Cathode Picture Tube (same as CRT), Color Picture Tube (a color CRT), or the display manufacturer Chunghwa Picture Tubes in Taiwan.
Crystal Cycle: The boom-and-bust cycle seen in the LCD industry. The cycle results from alternating periods of oversupply and shortage, creating downward and upward pressure on panel prices. When prices are high, manufacturers invest in more production facilities which results in overproduction. Prices drop, creating more demand, which causes manufacturers to invest in even more production facilities to satisfy the demand. Then the cycle repeats.