Term (Acronym) [units]: Definition
Backlight: The light source for a transmissive LCD, located directly behind the LCD (for small or very large LCDs), or at the side of the LCD (for small or medium LCDs). The light from the backlight is either blocked (black) or passed (white) by the LCD cell. LEDs or EL panels are used for most backlights smaller than five inches in diagonal size; fluorescent lamps are used for most backlights larger than five inches.
Backlight Unit (BLU): The complete backlight assembly for an LCD display, typically consisting of the light source, a light guide, reflectors, brightness enhancement films or prism sheets (if used), a diffuser and a housing.
Backplane: The portion of a display that controls the pixels located in the frontplane. In an AMLCD or AMOLED display, the backplane contains the thin-film transistors (TFTs).
Bezel: A metal or plastic frame that surrounds the active area of a display. The bezel protects the edges of the display and any circuitry that may be located there.
Bill Of Materials (BOM): A detailed list of materials and components that make up an assembly. The BOM is a building block of the manufacturing information system and is often used in cost accounting.
Birefringence: Birefringence, also called double-refraction, is the decomposition of a single light ray into two light rays when it passes through certain types of material, depending on the polarization of the light. Birefringent materials are used in many devices that manipulate the polarization of light, such as retardation films and polarizing prisms.
Bit Depth: See Color Depth .
Black Luminance: The amount of light that a display emits when every pixel is set to black. Ideally this is zero, but LCDs (in particular) have problems with leakage of light from the backlight. Emissive displays such as PDPs and OLEDs typically have much lower black luminance levels.
Black Matrix (BM): A patterned layer in an LCD’s color filter assembly whose purpose is to prevent light leakage and improve contrast.
Blu-ray: One of two next-generation (post-DVD) optical disc formats designed for storage of high-definition video and data. Developed by Sony. The name is derived from the blue-violet laser used to read and write the disc.
Brightness: The dimension of color that is referred to on an achromatic scale ranging from black to white; also called luminous intensity or lightness.
Brightness Enhancement Film (BEF): A prism film that increases a display's brightness. 3M is the dominant supplier of BEF, although because of recent patent expirations, many new suppliers are entering the market.