Question of difference between LCD and the segment displays?

Discussion in 'General Electronics Chat' started by nepdeep, Dec 29, 2012.

  1. nepdeep

    Thread Starter Active Member

    Sep 14, 2011
    I worked last December to build a digital clock project. We used multiplexer to swtich the counter value to the respecitve seven segment displays simultaneously....recently I found one amazing thing about LCDs...but totally confused....they say every pixel is made of RGB blocks......

    1)are these like kind of LEDS...??
    ya not leds but may be crystals or something!!??

    2) I dont think there are many data lines for the LCD...okey let us say we have 50(really 50) datalines for LCD and it has to control 1980 X 1200 pixels=2376000 blocks.....mann!!!that much witch just 50 datalines.....

    so 2376000/50=47520

    50 pixels 47520 less than 20 ms for human eye or 50 Hz at least...

    so it should be that fast it should turn on right data on right pixel each 20 ms 47520 times....mannn....that is a damm job...

    I think I am missing some please..
  2. absf

    Senior Member

    Dec 29, 2010
    Well, what you said are all quite true... But we have smart engineers to have designed dedicated LSI chips for both the text LCD and GLCD and have made them the de factor standard for the LCD display communities. Just like the remote control standards for TV, Audio, DVD there're RC5, Matsushita, SONY, Toshiba etc standard codes......

    Now we only need to worry about the 14-20 wires that came out of the LSI and let the LSI take care of the timming and multiplexing of the ROWs and COLUMNS of the LCD display.

  3. Audioguru


    Dec 20, 2007
    An LED display EMITTS light. It uses electrical power to make the light.
    An LCD display PASSES or blocks EXISTING light so it uses almost no power. Its fluorescent or LED backlight uses lots of power.

    New TVs have LED displays? Is every pixel an LED? Or is it an LCD display with an LED backlight?
  4. Papabravo


    Feb 24, 2006
  5. crutschow


    Mar 14, 2008
    They are LCD displays with an LED (instead of a fluorescent) backlight.

    There is a new type of display which uses OLEDs as an emitter for every pixel. My understanding is that they have very good brightness and color accuracy. But at present they are quite expensive ($10kUS for a 55 inch).