adjustment of complicated IRQ settings -- for add-on peripherals. USB does away with "port
gridlock." Without USB, PCs are normally limited to one printer, two Com port devices (usually a
mouse and modem), one Enhanced Parallel Port add-on (scanner or video camera, for example), and
a joystick. More and more peripherals for multimedia computers come on the market every day.
With USB, up to 127 devices can run simultaneously on one computer. USB permits "hot plug-in." No need
to shut down, plug in, reboot and run set up to install peripherals. No need to go through the reverse
process to unplug a device. Bottom line: USB transforms today's "Plug-and-Pray" into true Plug-and-Play!
Q:
What is a USB hub ?
A:
A USB hub provides additional connections to the Universal Serial Bus. A hub's upstream port
connects a hub to the host, usually a PC. Multiple downstream ports in a hub allows connection to
another hub or device, such as a USB keyboard, camera or printer.
RETURN TO TOP OF THE PAGE
LCD Panel Technology
Q:
What is Liquid Crystal Display?
A:
A Liquid Crystal Display (LCD) is an optical device that is commonly used to display ASCII
characters and images on digital items such as watches, calculators, portable game consoles etc.
LCD is the technology used for displays in notebook and other small computers. Like light-emitting
diode and gas-plasma technologies, LCD allows displays to be much thinner than cathode ray tube
(CRT) technology. LCD consumes much less power than LED and gas-display displays because
they work on the principle of blocking light rather than emitting it.
Q:
How are LCDs made?
A:
LCDs are created from two glass plates separated from each other at a distance of a few
microns. Plates are filled with liquid crystal, then seals together. The top plate is colored with a RGB
pattern to make the color filter. Then polarizers are 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 electromagnetic wave.
Electric and magnetic fields oscillate in a direction perpendicular to the propagation of the light
beam. The direction of these fields is called "polarization direction." Normal or non-polarized light
has fields in several directions; polarized light has a field in only one direction.
FAQs (Frequently Asked Questions)
file:///D|/K1/english/180p2b/safety/saf_faq.htm (5 of 8) [3/26/2003 10:58:36 AM]
