HOW AN LCD PANEL WORKS

      After turning ON the power switch, power board sends (5V) standby supply voltage to microprocessor IC waiting for ON signal from keyboard or from the remote control.    When an ON signal either from keyboard or remote control is detected, microcontroller will send On control signals to Power board.  Then Power board sends [5Vsc, 12Vsc, 24V and Rly On, Vs On] to PCBs working.  This time, VIF will send signals to display back light, OSD on the panel and start to search available signal sources.  If the audio signals input, them will be amplified by audio amplifier and transmitted to speaker.  


     If some abnormal signals are detected, for example (over volts, over current, over temperature and under volts), the system will be shut down by Power Off.  


LCD BASIC DISPLAY THEORY


     When an electrical field is applied to the Liquid Crystal {LC} planes, molecules re-align so that, they are parallel to the electrical field.  This electrical process is know as [Twisted Nematic Field Effect] or (TNFE).  In this alignment, polarized light is not twisted as it passes through the LC material.  If front polarizer is oriented perpendicular to rear polarizer, light will pass through the energized display but will be blocked by the rear polarizer.  An LCD in this form is acting as a light shutter.  


     Displays with various characters are created by etching away the conductive surface that was originally deposited on the glass.   Etched areas becomes the displays' background; unetched areas become the displays character.