Glossary of Terms:

Active Matrix LCD - Individual pixels of the display are controlled by thin film transistors, which are deposited directly onto the glass substrate. Each pixel is therefore driven in a static mode, resulting in very high contrast and viewing angle.

Annunciator - A word or special symbol which is driven as a single segment

Array Process - Method of manufacturing whereby displays are arranged in rows and columns on a large laminate, and separated after they are filled with LCD fluid.

Backplane - The common electrode connection. There can be multiple backplanes in a multiplexed display.

Common Plane - See Backplane

Contact Ledge - The area along the edge of the parts where electrical connections are made.

Contrast Ratio - The ratio of the luminance between the dark and light areas of the display.

Dual in Line Pins (DIL) - Two rows of pins attached along parallel sides of a display.

Direct Drive - A method of driving a display whereby individual segments are driven from separate edge connections.

Elastomeric Connectors - A thin conductive material used to make connections between an LCD and a PC board.

First Minimum - An LCD construction technique where the cell geometry is optimized for maximum contrast and viewing angle. The geometry is different for each LCD fluid.

Font - The style of a letter or digit.

Ghosting - A condition where segments which are in the "off" condition become slightly visible.

Heat Seal Connector - A thin flexible cable used to connect the LCD to the PC board.

Image Area - The total area bounded by the display characters

Ink Overlay - The process of applying opaque, colored inks to the display to provide colors, or highlight certain areas of annunciators.

Isocontrast Plot - Usually a polar plot showing contrast ratio versus viewing angle. The individual curves represent points of equal contrast.

Liquid Crystal Fluid- An organic material which has both liquid and crystalline properties.

Module - An LCD which includes a PCB, driver electronics, bezel, and possibly a backlight.

Multiplex (Mux) - A method of driving a display whereby multiple segments are driven from the same edge connection.

Negative Image - A display which has a dark background and lighter active segments, i.e. clear characters on a black background.

Pixel - An individual active segment.

Polarizer - A stretched polymer which transmits light in only one axis. A typical display has polarizers on the front and back.

Positive Image - A display which has a light background and darker active segments, i.e. black characters on a silver background.

Reflective - A viewing mode which uses ambient or other front lighting to provide the illumination for the display.

Segment - An active area within the display which can be turned on and off. This can be a single segment of a 7-segment character, an annunciator, or a pixel in a dot matrix array.

Static Drive - See Direct Drive

Supertwist (STN) - A type of display which uses fluids which "twist" greater than 90o. An STN display has improved viewing angles and contrast at high multiplex rates.

Transflective - A viewing mode which can use ambient light or backlighting to provide the illumination for the display.

Transmissive - A viewing mode which cannot use any type of front lighting to provide the illumination for the display, it therefore must use a backlight.

Twisted Nematic (TN) - A type of display where the liquid crystal fluid rotates the plane of polarization 90o.

Viewing Area - The area of a display which is visible through a bezel or cut-out in an instrument.

Viewing Angle - The preferred angle of viewing a display, usually described in comparison to a clock face, i.e. 12 o'clock for above the normal, or 6 o'clock for below the normal.