its about LCD & LED..

1. Monitors,
LCD & LED
PRESENTED BY
RAMEESHA SADAQAT

2. Contents
 Definition
 History
 Structure
 Diagram
 Differences

3. Monitor
 A display screen that provides a visual output.
 Monitors are very important because without them we
wouldn’t be able to see and do anything.

4. History
 VDT and terminals monitors introduced in 1980’s. They
only displayed text in two colors usually black and green.
 In 1981, IBM introduced the CRT monitors which could
display 16 colors.
 XGA and UXGA introduced in 1987 can display up to 16
million colors.
 In 1990’s LCD monitors were introduced.

5. LCD
(liquid crystal display)
 LCD’s are super thin displays that are used in laptops,
computer screens and flat panel monitors.
 LCD screens are based on the principle of blocking light
(rather than emitting it), they use up much less power
than standard CRT (Cathode-Ray Tube) monitors.

6. Structure
 The inside of an LCD monitor basically comprises of 3 units:
 1. LCD panel (the screen)
 2. Backlight (a CCFL or cold cathode fluorescent light bulb)
 3. Inverter (power supply unit)
 The internal hardware of an LCD monitor is structured in such a way that
the inverter supplies power to the backlight bulb, which in turn lights up
the image you see on the LCD screen.
 There are other components as well -- like the transformer, analog/digital
converter and external DVI/VGA ports -- but the above 3 are the main
components

7. Diagram

8. LED
(light emitting diode)
 An LED is an electronic device that emits light when an
electrical current is passed through it.
 Early LEDs produced only red light, but modern LEDs can
produce several different colors, including red, green, and
blue (RGB) light. Recent advances in LED technology have
made it possible for LEDs to produce white light as well.

9. Structure
 LED display is made up of two parts:
 Main LED panel which is composed by several LED display
units(Led cabinet or LED panel)that can connected together.
This part is the main body of the LED display.
 Another part is the controller. The controller can also be
divided into two parts:
 Control board( hardware)
 Control system( software).

10. Diagram

11. Difference bw LCD & LED
LCD
 LCD displays are not self-illuminating.
 They need a backlight in order to
produce a visible picture.
 Regular LCDs are backlit by CCFLs
(Cold Cathode Florescent Lamps).
 These lights resemble the florescent
light tubes used for lighting, and are
arranged in horizontal rows behind
the LCD screen.
LED
 An LED TV still uses an LCD display, but
instead of CCFLs, it is illuminated using an
array of LED lights.
 LED lights are smaller and thinner than
CCFLs, an LED monitor can be thinner and
more lightweight than an LCD monitor that
uses CCFLs.
 LED lights are also more energy efficient
than CCFL lights, and perform better as
well.
 LED lights are only illuminating when they
need to be, so contrast and black levels on
an LED monitor are usually superior to
those found on an LCD display that uses
CCFL lights.

12. THANK
YOU