Philips 190PS User Manual

Also see for 190P5: Declaration of conformity User manual

Contents

FAQs (Frequently Asked Questions)LCD Panel TechnologyQ: What is a Liquid Crystal Display?A: A Liquid Crystal Display (LCD) is an optical device that is commonly used to displayASCII characters and images on digital items such as watches, calculators, portable gameconsoles, etc. LCD is the technology used for displays in notebooks and other smallcomputers. Like light-emitting diode and gas-plasma technologies, LCD allows displays tobe much thinner than cathode ray tube (CRT) technology. LCD consumes much less powerthan LED and gas-displays because it works on the principle of blocking light rather thanemitting it.Q: How are LCDs made?A: LCDs are created from two glass plates separated from each other at a distance of a fewmicrons. The plates are filled with liquid crystal and then sealed together. The top plate iscolored with an RGB pattern to make the color filter. Polarizers are then glued to both plates.This combination is sometimes called 'glass' or 'cell.' The LCD cell is assembled into a'module' by adding the backlight, driver electronics and frame.Q: What is polarization ?A: Polarization is basically directing light to shine in one direction. Light is electromagneticwaves. Electric and magnetic fields oscillate in a direction perpendicular to the propagationof the light beam. The direction of these fields is called the 'polarization direction'. Normal ornon-polarized light has fields in several directions; polarized light has a field in only onedirection.Q: What differentiates passive matrix LCDs from active matrix LCDs?A: An LCD is made with either a passive matrix or an active matrix display grid. An activematrix has a transistor located at each pixel intersection, requiring less current to controlthe luminance of a pixel. For this reason, the current in an active matrix display can beswitched on and off more frequently, improving the screen refresh time (your mouse pointerwill appear to move more smoothly across the screen, for example). The passive matrix LCDhas a grid of conductors with pixels located at each intersection in the grid.Q: How does a TFT LCD Panel work?A: On each column and row of the TFT LCD panel, a data source drive and a gate drive areattached, respectively. The TFT drain of each cell is connected to the electrode. Themolecular arrangement of liquid crystal elements differ according to whether it is impressedfile:///D|/My%20Documents/dfu/W9/english/190p5/safety/saf_faq.htm (8 of 10)2004-09-21 9:08:31 AM