資料來源 : WordNet®

liquid crystal display
     n : a digital display that uses liquid crystal cells that change
         reflectivity in an applied electric field; used for
         portable computer displays and watches etc. [syn: {LCD}]

資料來源 : Free On-Line Dictionary of Computing

liquid crystal display
     
         (LCD) An electro-optical device used to display
        digits, characters or images, commonly used in digital
        watches, calculators, and portable computers.
     
        The heart of the liquid crystal display is a piece of {liquid
        crystal} material placed between a pair of transparent
        {electrodes}.  The liquid crystal changes the phase of the
        light passing through it and this phase change can be
        controlled by the {voltage} applied between the electrodes.
        If such a unit is placed between a pair of {plane polariser}
        plates then light can pass through it only if the correct
        voltage is applied.  Liquid crystal displays are formed by
        integrating a number of such cells, or more usually, by using
        a single liquid crystal plate and a pattern of electrodes.
     
        The simplest kind of liquid crystal displays, those used in
        digital watches and calculators, contain a common electrode
        plane covering one side and a pattern of electrodes on the
        other.  These electrodes can be individually controlled to
        produce the appropriate display.  Computer displays, however,
        require far too many pixels (typically between 50,000 and
        several millions) to make this scheme, in particular its
        wiring, feasible.  The electrodes are therefore replaced by a
        number of row electrodes on one side and column electrodes on
        the other.  By applying voltage to one row and several columns
        the {pixels} at the intersections are set.
     
        The pixels being set one row after the other, in {passive
        matrix} displays the number of rows is limited by the ratio of
        the setting and fading times.  In the setup described above
        (known as "{twisted nematic}") the number of rows is limited
        to about 20.  Using an alternative "{supertwisted nematic}"
        setup {VGA} quality displays (480 rows) can be easily built.
        As of 1995 most {notebook computers} used this technique.
     
        Fading can be slowed by putting an active element, such as a
        {transistor}, on the top of each pixel.  This "remembers" the
        setting of that pixel.  These {active matrix} displays are of
        much better quality (as good as {CRTs}) but are much more
        expensive than the passive matrix displays.
     
        LCDs are slimmer, lighter and consume less power than the
        previous dominant display type, the {cathode ray tube}, hence
        their importance for {portable computers}.
     
        (1995-12-09)